RU2397017C2 - Catalyst precursors not containing halides - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of preparing a catalyst or procatalyst suitable for use in production of alkenylalkanoates, to a catalyst composition for production of alkenylalkanoates and to a method of producing alkenylalkanoates. The invention describes a method of preparing a catalyst or procatalyst which involves bringing at least one solution of a catalyst component precursor which contains palladium or gold into contact with support material, where at least one solution of the catalyst component precursor is an aqueous solution which contains one or more of Pd(NH₃)₂(NO₂)₃, Pd(NH₃)₄(OH)₂, Pd(NH₃)₄(NO₃)₂, Pd(NH₃)₄(OAc)₂, Pd(NH₃)₂(OAc)₂, Pd(NH₃)₄(HCO₃)₂₎ and of NaAuO₂, KAuO₂, NMe₄AuO₂ and HAu(NO₃)₄ in nitric acid or their combinations and reduction of palladiuim or gold when the reducing medium is brought into contact with the support material. The invention describes a catalyst composition which contains support material containing at least palladium and gold which is brought into contact with the support material to obtain a catalyst or procatalyst using the method described above. Described also is a method of producing alkenylalkanoates which involves bringing starting material which contains alkene, alkanoic acid and oxidising agent into contact with a catalyst or procatalyst described above.

EFFECT: reduced amount of by-products and more efficient production of alkenylalkanoates.

32 cl, 6 tbl, 15 ex

Description

Priority Request

This application claims the benefits of provisional application US No. 60/530937, filed December 19, 2003, which, therefore, is incorporated herein by reference.

Technical field

The present invention relates to catalysts, methods for producing catalysts and methods for producing alkenyl alkanoates. More specifically, the invention relates to methods for producing vinyl acetate.

State of the art

Certain alkenyl alkanoates, such as vinyl acetate (VA), are marketable chemical products in high demand in their monomeric form. For example, VA is used to produce polyvinyl acetate (PVAc), which is commonly used for the manufacture of adhesives and accounts for a large share of VA use. Other uses for VA include polyvinyl alcohol (PVOH), ethylene vinyl acetate (EVA) copolymers, vinyl acetate-ethylene copolymers (VAE), polyvinyl butyral (PVB), ethylene vinyl alcohol copolymer (EVOH), polyvinyl formal (PVF) and vinyl chloride-vinyl acetate copolymer. PVOH is commonly used in the manufacture of textiles, films, adhesives and photosensitive coatings. In the manufacture of films and insulation for wires and cables in a certain amount often use EVA. The main applications for the vinyl chloride-vinyl acetate copolymer include coatings, paints, and VAE, in a certain amount containing VA, is often used in adhesives. VAE, which contains more than 50 percent VA, is mainly used as cement additives, paints and adhesives. PVB is mainly used in the manufacture of the lower layer in laminated windshields, coatings and printing inks. EVOH is used in the manufacture of impermeable films and structural polymers. PVF is used in the manufacture of enamel for wires and magnetic tape.

Since VA is the basis for the manufacture of such a large number of commercially significant materials and products, the demand for VA is great, and VA is often produced on a relatively large scale, for example, in the amount of 50,000 metric tons or more per year. This large-scale production means that significant savings are possible due to an increase in the scale of production, and relatively subtle changes in the method, process conditions or catalyst characteristics can have a significant cost-saving effect on VA production.

A large number of alkenyl alkanoate production methods have been reported. For example, in the preparation of VA, a widely used technique involves a catalyzed gas phase reaction between ethylene, acetic acid and oxygen, as can be seen from the following reaction:

C ₂ H ₄ + CH ₃ COOH + 0.5 O ₂ → CH ₃ COOCH = CH ₂ + H ₂ O.

It is possible to undergo several adverse reactions, including, such as the formation of CO ₂ . The results for this reaction are discussed in terms of yield in grams per hour per unit volume of catalyst (STY), where STY is the number of grams of VA produced per liter of catalyst per hour of reaction time (g / l · hour).

The composition of the feedstock material can vary widely. Typically, the feedstock comprises 30-70% ethylene, 10-30% acetic acid and 4-16% oxygen. The feedstock may also include inert materials such as CO ₂ , nitrogen, methane, ethane, propane, argon and / or helium. The main limitation on the composition of the feedstock is that the level of oxygen in the product stream leaving the reactor must be sufficiently low so that the composition of the stream does not fall within the flammability range. The level of oxygen in the products is influenced by the level of oxygen in the flow of materials of the feedstock, the degree of conversion of O ₂ in the reaction and the amount of any inert material in the products.

A gas-phase reaction is carried out when the feed stream is passed into reactors with a fixed catalyst bed either over the bed or through it. Favorable results were obtained using reaction temperatures in the range from 125 ° C to 200 ° C, while the usual pressures during the reaction are 1-15 atmospheres.

Although these systems provide adequate yields, there remains a need for reduced by-product production, increased VA production and reduced energy consumption during production. One approach is to improve the performance of the catalyst, in particular with regard to selectivity for the production of CO ₂ and / or catalyst activity. Another approach is to modify the reaction conditions, such as the ratio between the components of the feedstock materials, the degree of conversion of O ₂ into the reaction, the space velocity (SV) for the feed stream of the feedstock, and operating temperatures and pressures.

The formation of CO ₂ is one aspect that can be reduced by the use of improved catalysts. The selectivity for CO ₂ production is the percentage of ethylene converted that has been converted to CO ₂ . The decrease in selectivity with respect to the production of CO ₂ makes it possible to obtain more VA per unit volume and per unit time in existing plants, even if all other reaction conditions are maintained at the same level.

The VA production volume in a particular reaction system is influenced by several other factors, including catalyst activity, the ratio between the components of the feedstock materials, the degree of conversion of O ₂ into the reaction, the space velocity (SV) for the feed stream of the feedstock, and operating temperatures and pressures. All of these factors, as a result of their combined action, determine the yield in grams per hour per unit volume of catalyst (STY) in the reaction system, where STY is discussed when expressed in terms of the number of grams of VA obtained per liter of catalyst per hour of reaction time, or g / l ·hour.

In the general case, activity is a significant factor in determining STY, but other factors can also have a significant effect on STY. Typically, the higher the activity of the catalyst, the higher the STY value that the catalyst will be able to provide.

The O ₂ conversion is a measure of how much oxygen reacts in the presence of a catalyst. The degree of conversion of O ₂ is a temperature-dependent parameter, so that in general the degree of conversion increases with increasing reaction temperature. However, in parallel with increasing the degree of conversion of O ₂ , the amount of CO ₂ obtained also increases. Therefore, the degree of conversion of O _{2 is} chosen so as to achieve a balance between the desired amount of VA production and the amount of CO ₂ obtained. A catalyst having a higher activity means that the overall reaction temperature can be reduced while maintaining the same degree of conversion of O ₂ . Alternatively, a catalyst with higher activity will achieve a higher degree of conversion of O ₂ at a given temperature and space velocity.

It is common practice that one or more catalyst components supported on a relatively inert support material are used in the catalyst. In the case of VA catalysts, the catalyst components are usually a mixture of metals that can be uniformly distributed throughout the support material (“catalysts with an active zone throughout the material”), only on the surface of the support material (“catalysts with an active zone on the surface”), only beneath the surface of the carrier material (“catalysts with the structure of the core in the type of protein in the egg”) or in the core of the material of the carrier (“catalysts with the structure of the core in the type of yolk in the egg”).

Numerous different types of carrier materials have been proposed for use in the VA production catalyst, including silica, cerium doped silica, alumina, titanium dioxide, zirconia, and oxide mixtures. But studies on the differences between carrier materials have been conducted to a very small extent. In fact, only silica and alumina were mainly used as carrier materials on a commercial scale.

One metal combination suitable for catalysis in the preparation of VA is palladium and gold. Pd / Au catalysts provide adequate selectivity for CO ₂ production and activity, but there continues to be a need for improved catalysts to achieve the economies of scale that are possible with VA production.

One method for preparing Pd / Au catalysts typically includes the steps of impregnating the support with aqueous solutions of water-soluble salts of palladium and gold; carrying out the reaction between the impregnated water-soluble salts and a suitable alkaline compound, for example sodium hydroxide, to precipitate (often referred to as fixation) metal elements in the form of compounds insoluble in water, for example hydroxides; washing the fixed carrier material to remove non-fixed compounds and to purify the catalyst in another way from any potential poisons, for example chloride; recovering water-insoluble compounds using a conventional reducing agent such as hydrogen, ethylene or hydrazine; and adding an alkali metal compound such as potassium or sodium acetate.

Various modifications to this basic method have been proposed. For example, US Pat. No. 5,990,344 proposes sintering of palladium after its reduction to the free metal form. US Pat. No. 6,022,823 proposes the possible benefits of calcining a carrier in a non-reducing atmosphere after impregnation with both palladium and gold salts. WO 94/21374 proposes the possibility of pretreating a catalyst as a result of sequential heating in oxidizing, inert and reducing atmospheres after reduction and activation, but before its first use.

US Pat. No. 5,466,652 suggests the possibility of being suitable for impregnating a carrier material of palladium and gold salts that do not contain hydroxyl, halides and barium and are soluble in acetic acid. A similar proposal was made in US patent No. 4902823, that is, the use of halide-free and sulfur-free salts and palladium complexes soluble in unsubstituted carboxylic acids containing from two to ten carbon atoms is proposed.

US Pat. No. 6,486,370 proposes the use of a layered catalyst in a dehydrogenation process, wherein the support material in the inner layer is different from the support material in the outer layer. Similarly, US Pat. No. 5,935,889 proposes the suitability of a layered catalyst as acid catalysts. But nowhere is the use of layered catalysts proposed for the production of alkenyl alkanoates.

Summarizing the foregoing, we can say that the inventors proceeded from the awareness and appeal to the need for continuous implementation of improvements in the field of VA catalysts to provide improved VA production at a lower cost.

SUMMARY OF THE INVENTION

The present invention addresses at least four different aspects related to the structure of the catalysts, methods for producing these catalysts, and methods for using these catalysts to produce alkenyl alkanoates. Separately or jointly in combination, various aspects of the invention are aimed at improving the production of alkenyl alkanoates and VA, in particular, including reducing the number of by-products and improved production efficiency. A first aspect of the present invention relates to a unique palladium / gold-containing catalyst or procatalyst (optionally calcined) that contains rhodium or another metal. The second aspect relates to a palladium / gold-containing catalyst or procatalyst, the basis of which is a layered carrier material, where one layer of carrier material essentially does not contain catalytic components. A third aspect relates to a palladium / gold-containing catalyst or procatalyst deposited on a support material containing zirconia. A fourth aspect relates to a palladium / gold-containing catalyst or procatalyst, which are obtained from catalytic components essentially free of chlorides.

Detailed description

Catalysts

For the purposes of the present invention, the catalyst is any support material that contains at least one catalytic component and which is capable of catalyzing the reaction, while the procatalyst is any material that results from any of the production steps discussed herein catalyst.

The catalysts and procatalysts of the present invention may include those materials that are characterized by at least one of the following features: 1) the catalyst will be a palladium and gold-containing catalyst, which contains at least one other catalyst component, for example, rhodium, where one or more of the catalytic components is subjected to calcination; 2) the catalyst will be deposited on a layered carrier; 3) the catalyst will be deposited on a carrier material containing zirconia; 4) the catalyst will be obtained using chloride-free precursors, or any combination of the above features. Accordingly, the efficient use of the catalyst should help to improve selectivity with respect to the production of CO ₂ , activity, or both at the same time, especially with regard to the production of VA.

You must understand that the present invention is described in the context of certain illustrative embodiments, but it can vary in any of several aspects depending on the needs in a particular application. By way of example and not by way of limitation, the catalysts may contain catalyst components uniformly distributed throughout the carrier material, or they may be catalysts with an active zone on the surface where the catalyst components are in a relatively thin surface shell covering the core of the carrier material. Catalysts with a protein-in-egg core structure may also be suitable, where the catalytic components are substantially at a distance from the center of the carrier material. Catalysts with a core structure of the yolk in egg type may also be suitable.

Catalytic components

In the General case, the catalysts and procatalysts of the present invention contain metals and, in particular, contain a combination of at least two metals. In particular, the combination of metals contains at least one from group VIIIB and at least one from group IB. It should be understood that the “catalytic component” is used to refer to a metal that ultimately gives the catalyst catalytic functionality, but this term also contains metal in various conditions, such as salt, solution, sol-gel, suspensions, colloidal suspensions, free metal, alloy, or combinations thereof. Preferred catalysts contain palladium and gold as catalyst components.

One embodiment of the catalyst includes a combination of catalyst components comprising palladium and gold in combination with a third catalyst component. The third catalyst component is preferably selected from group VIIIB, with Rh being most preferred. Other preferred catalysts include those in which the third catalyst component is selected from W, Ni, Nb, Ta, Ti, Zr, Y, Re, Os, Fe, Cu, Co, Zn, In, Sn, Ce, Ge, Ga and their combinations.

Another embodiment of the catalyst includes a combination of catalytic components, including parts of palladium, gold and rhodium. Instead of Rh, a third catalytic component can also be optionally included in this embodiment (according to the above list). In yet another embodiment, it is possible to use two or more catalyst components from the above list.

In one example, palladium and gold can be combined with Rh to form a catalyst that exhibits improved selectivity for CO ₂ (i.e., reduced CO ₂ formation) compared to Pd / Au based catalysts that lack Rh. In addition, the addition of Rh does not appear to adversely affect the activity of the catalyst. The selectivity for producing CO ₂ in a palladium, gold, and rhodium-containing catalyst can also be improved by calcining during the preparation of the catalyst and / or by using water-soluble halide-free precursors (both options are discussed below), although that both options are not required to obtain the effect of Rh.

The atomic ratio between the third catalyst component and palladium may be in the range of from about 0.005 to about 1.0, more preferably from about 0.01 to about 1.0. In one embodiment, the catalyst contains from about 0.01 to about 5.0 g of the third catalyst component per liter of catalyst.

Another preferred embodiment of the catalyst contains from about 1 to about 10 grams of palladium and from about 0.5 to about 10 grams of gold per liter of catalyst. The amount of gold is preferably in the range of from about 10 to about 125% (wt.) Based on the weight of palladium.

In one embodiment of ground catalysts, for atomized catalysts, atomic ratios between Au and Pd in the range of about 0.5 to about 1.00 may be preferred. The atomic ratio can be adjusted to strike a balance between activity and selectivity for CO ₂ production. The use of higher mass or atomic ratios of Au / Pd tends to favor the production of more active, more selective catalysts. Differently expressed, it is possible to say that a catalyst having an atomic ratio of approximately 0.6 is less selective with respect to the production of CO ₂ , but also has a lower activity compared to a catalyst having a ratio of approximately 0.8. The effect of the high atomic ratio Au / Pd on the ground carrier material can also be increased by using a relatively high excess of hydroxide ion, as discussed below with respect to the fixation step. The ground catalyst may be a catalyst in which the catalyst components are brought into contact with the support material, followed by particle size reduction (for example, by abrasion or grinding in a ball mill), or a catalyst in which the catalyst components are brought into contact with the support material as the particle size of the carrier material has been reduced.

In the case of catalysts with a core on the surface, the thickness of the surface shell formed by the catalytic components on the support material is in the range from about 5 μm to about 500 μm. More preferred ranges include from about 5 microns to about 300 microns.

Media Materials

As indicated, in one aspect of the invention, the catalyst components of the present invention will generally be applied to a support material. Suitable carrier materials typically include materials that are substantially uniform in nature, or a mixture of materials. In General, the materials of the carrier are usually inert in the reaction. The carrier materials may consist of any suitable substance, preferably selected so that the carrier materials have a relatively high surface area per unit mass or volume, such as for a porous structure, molecular sieve structure, honeycomb structure, or other suitable structure. For example, the support material may comprise silica, alumina, silica-alumina, titanium dioxide, zirconia, niobium dioxide, silicates, aluminosilicates, titanates, spinel, silicon carbide, silicon nitride, carbon, cordierite, steatite, bentonite, clay , metals, glass, quartz, pumice, zeolites, non-zeolitic molecular sieves, combinations thereof and the like. Any of the various crystalline forms of the materials may also be suitable, for example alpha or gamma alumina. Most preferred are carrier materials containing silica and zirconia. In addition, multilayer support materials are also suitable for use in the present invention.

The carrier material in the catalyst of this invention may consist of particles having any of various regular or irregular shapes, such as the shape of spheres, tablets, cylinders, discs, rings, stars, or other shapes. The carrier material may have dimensions, such as diameter, length or width, in the range of from about 1 to about 10 mm, preferably from about 3 to about 9 mm. In particular, in the case of a regular shape (for example, spherical) as its preferred largest size, a value in the range of about 4 mm to about 8 mm will take place. In addition, crushed or powdered carrier material may be suitable, such that the carrier material has a regular or irregular shape with a diameter in the range of from about 10 microns to about 1000 microns, with preferred sizes in the range of from about 10 to about 700 microns, and most preferred sizes range from about 180 microns to about 450 microns. It is possible to use larger or smaller sizes, as well as polydisperse sets of particle sizes. For example, in the case of a fluidized catalyst bed, a preferred size range will include a range of 10 to 150 microns. In the case of precursors used in layered catalysts, a size range of 10 to 250 microns is preferred.

The specific surface areas possible for the support of the catalyst components, as measured by the BET method (Brunauer-Emmett-Teller), can generally be in the range from about 1 m ² / g to about 500 m ² / g, preferably from about 100 m ² / g to about 200 m ² / g. For example, in the case of a porous support, the pore volume of the support material can generally be in the range of from about 0.1 to about 2 ml / g, and preferably from about 0.4 to about 1.2 ml / g. Preferred, but not required, is an average pore size in the range of, for example, from about 50 to about 2000 angstroms.

Examples of suitable silica-containing support materials include KA160 from Sud Chemie, Aerolyst 350 from Degussa and other grades of fumed or micropore-free silica having particle sizes ranging from about 1 mm to about 10 mm.

Examples of suitable carrier materials containing zirconia include materials from NorPro, Zirconia Sales (America), Inc., Daichi Kigenso Kagaku Kogyo and Magnesium Elektron Inc (MEI). Suitable carrier materials containing zirconia have a wide range of specific surface areas from less than about 5 m ² / g to more than 300 m ² / g. Preferred carrier materials containing zirconia are characterized by specific surface areas ranging from about 10 m ² / g to about 135 m ² / g. The carrier materials may have surfaces subjected to a calcining step in which the starting material of the carrier is heated. Heating (for example, calcination) leads to a decrease in the specific surface area of the carrier material. This provides a method for creating carrier materials characterized by specific surface areas, which in other cases would not have been easy to obtain from suppliers.

In yet another embodiment, it is contemplated to use at least a plurality of combinations of carrier materials, each of which has its own characteristic. For example, at least two carrier materials (e.g. zirconia) having different characteristics can exhibit different activities and selectivities with respect to the production of CO ₂ , thus making it possible to obtain catalysts having the desired set of characteristics, i.e., can be found a balance between catalyst activity and catalyst selectivity for CO ₂ production.

In one embodiment, several different carriers are used in a layered configuration. Using any of several different approaches, it is possible to obtain a layered structure, such as a plurality of lamellas, which are generally flat, wavy or combined. One specific approach is to use sequentially spanning layers with respect to the original core layer. In the general case, in the present invention, laminated carrier materials typically include at least an inner layer and an outer layer at least partially surrounding the inner layer. The outer layer preferably contains substantially more catalytic components compared to the inner layer. In one embodiment, the inner and outer layers are made from various materials; but the materials may be the same. While the inner layer may be non-porous, other embodiments include an inner layer that is porous.

The layered support material preferably results in a catalyst shape with a core on the surface. But the laminated support material establishes a well-defined boundary between the surfaces of the support material that contain catalytic components and the surfaces that do not contain them. In addition, the outer layer may be consistently formed having a desired thickness. The boundary and the uniform thickness of the outer layer together result in a catalyst with an active zone on the surface, i.e. a surface shell formed by catalytic components, which is characterized by a uniform and known thickness.

Several techniques are known for creating layered carrier materials, and these include those described in US Pat. Nos. 6486370; 5935889 and 5200382, each of which is incorporated herein by reference. In addition, in one embodiment, the materials of the inner layer are not substantially impervious to liquids, for example, in the case of metals, including the following, but not limited to: aluminum, titanium, and zirconium. Examples of other materials for the inner layer include, but are not limited to: alumina, silica, silica-alumina, titania, zirconia, niobium, silicates, aluminosilicates, titanates, spinel, silicon carbide, silicon nitride, carbon, cordierite, steatite, bentonite, clays, metals, glass, quartz, pumice, zeolites, non-zeolitic molecular sieves, and combinations thereof. In particular, silica and KA160 are the preferred inner layer.

These materials that make up the inner layer can be in a variety of forms, such as regular shaped particles, irregular shaped particles, granules, discs, rings, stars, wagon wheels, honeycomb structures or other shaped bodies. Preferred is an inner layer in the form of a spherical particle. The inner layer, with or without being spherical, has an effective diameter in the range of from about 0.02 mm to about 10.0 mm, and preferably from about 0.04 mm to about 8.0 mm.

The outermost layer in any multilayer structure is a layer that is porous, characterized by a specific surface area in the range of from about 5 m ² / g to about 300 m ² / g. The material of the outer layer is metal, ceramic, or a combination thereof, and in one embodiment, it is selected from alumina, silica, silica-alumina, titania, zirconia, niobium dioxide, silicates, aluminosilicates, titanates, spinel, silicon carbide , silicon nitride, carbon, cordierite, steatite, bentonite, clays, metals, glasses, quartz, pumice, zeolites, non-zeolitic molecular sieves and combinations thereof, and preferably it contains alumina, silica, silica / alumina minium, zeolites, non-zeolitic molecular sieves (NZMS), titanium dioxide, zirconia and mixtures thereof. Specific examples include zirconia, silica and alumina, or combinations thereof.

Although the outer layer usually surrounds substantially the entire inner layer, this is not necessary, and selective coating of the inner layer with the outer layer is possible.

The outer layer can be suitably applied as a coating to the layer below it. In one embodiment, a suspension of the material of the outer layer is used. The coating of the inner layer using a suspension can be carried out in accordance with methods such as rolling, dipping, spraying, etching, other methods of applying a suspension coating, combinations thereof and the like. One preferred technique involves using a fixed or fluidized bed of particles of the inner layer and spraying the suspension in the layer to apply a uniform coating to the particles. The suspension can be applied repeatedly in small amounts with intermediate drying to obtain an outer layer that is highly uniform in thickness.

The suspension used to coat the inner layer may also contain any of several additives, such as a surfactant, an organic or inorganic binder, which promotes the adhesion of the outer layer to the layer below it, or a combination thereof. Examples of this organic binder include, but are not limited to, PVA, hydroxypropyl cellulose, methyl cellulose, and carboxymethyl cellulose. The amount of organic binder that is added to the suspension may vary, as in the range from about 1% wt. up to about 15% wt. when calculating the mass of the combination of the outer layer and the binder. Examples of inorganic binders are selected from an alumina-based binder (e.g., Bohmite), silica-based binder (e.g., Ludox, Teos), a zirconia-based binder (e.g., zirconia or colloidal zirconia), or combinations thereof. Examples of silica binders include silica sol and silica gel, while alumina binders include alumina sol, bentonite, bomite and aluminum nitrate. The amount of inorganic binder may be in the range from about 2% wt. up to about 15% wt. when calculating the mass of the combination of the outer layer and the binder. The thickness of the outer layer may range from about 5 microns to about 500 microns, and preferably from about 20 microns to about 250 microns.

As soon as the outer layer is coated on the inner layer, the resulting layered carrier will be dried in such a way as by heating at a temperature in the range of from about 100 ° C to about 320 ° C (for example, over a period of time of range from about 1 to about 24 hours), and after that it can optionally be calcined at a temperature in the range of from about 300 ° C to about 900 ° C (for example, over a period of time duration in the range of from about 0.5 to about 10 hours) to improve the adhesion between the outer layer and the layer located under it, at least on part of their surface and obtain a layered catalyst carrier. The drying and calcining stages can be combined in one stage. The resulting layered support material can be brought into contact with the catalytic components in the same way as any other support material in the preparation of the catalysts, as described below. Alternatively, the support material of the outer layer is brought into contact with the catalytic components before it is applied as a coating to the layer below it.

In yet another embodiment of the layered carrier, a second outer layer is added to cover the initial outer layer and to produce at least three layers. The material of the second outer layer may be the same as the material of the first outer layer, or may be different from it. Suitable materials include those discussed in relation to the first outer layer. The method for applying the second outer layer may be the same as or different from the method used for applying the middle layer, and suitable methods include those discussed with respect to the first outer layer. Upon receipt of the second outer layer, it is appropriate to use the described organic or inorganic binders.

The initial outer layer may or may not contain catalytic components. Similarly, the catalyst components may or may not contain a second outer layer. If both outer layers contain a catalytic component, then different catalytic components are preferably used in each layer, although this is not necessary. In one preferred embodiment, the initial outer layer does not contain a catalyst component. The introduction of the catalytic component into contact with the outer layers can be accomplished by impregnation or by spray coating, as described below.

In embodiments in which the initial outer layer comprises a catalytic component, one way of obtaining this is to bring the catalyst component into contact with the material of the initial outer layer before the material is applied to the inner layer. The second outer layer can be applied to the initial outer layer, free of impurities or containing a catalytic component.

To obtain a three-layer carrier material in which one or more of the outer layers contain catalytic components, other suitable techniques may be used. Indeed, restrictions are not imposed on the laminate of the carrier in the form of the presence of three layers, and it may include four, five or more layers, of which all or some may contain catalytic components.

In addition, the number and type of catalytic components can vary from layer to layer, which change when moving from layer to layer in a laminated support material, other characteristics (e.g. porosity, particle size, specific surface area, pore volume and the like) carrier material.

Catalyst Preparation Methods

In general, the method includes contacting the catalyst components with the support material and reducing the catalyst components. Preferred methods of the present invention include impregnating the carrier material with the catalyst components, calcining the carrier material containing the catalyst components, reducing the catalyst components, and modifying the reduced catalyst components on the carrier material. Additional steps may also be included in the process for preparing the catalyst or procatalyst, such as fixing the catalytic components onto the support material and washing the fixed catalyst components. Some of the steps listed above are optional, while others can be omitted (for example, the washing and fixing steps). In addition, some steps can be repeated (for example, several stages of impregnation or fixation), and the order of the steps may differ from that given above (for example, the reduction step may precede the calcination step). To some extent, the contacting step will determine what subsequent steps will be required to obtain the catalyst.

Stage of contact

One specific approach to contacting is an approach related to whether a catalyst or procatalyst with a core structure of the yolk in egg type will be obtained, whether a catalyst or procatalyst with a core structure of the protein in egg type will be obtained whether to obtain a catalyst or procatalyst with a core throughout the material, or will receive a catalyst or procatalyst with a core on a surface or a combination thereof. In one embodiment, preferred are techniques that provide catalysts with a core on the surface.

The contacting step can be carried out using any of the carrier materials described above, with silicon dioxide, zirconia and laminated carrier materials containing zirconia being most preferred. The contacting step is preferably carried out under ambient temperature and pressure conditions; however, it is possible to use low or high temperatures or pressures.

In one preferred step of contacting, the support material is impregnated with one or more aqueous solutions of the catalyst components (called precursor solutions). The physical state of the carrier material during the contacting step may be a dry solid, suspension, sol-gel, colloidal suspension, and the like.

In one embodiment, the catalyst components contained in the precursor solution are water soluble salts obtained from the catalyst components, including but not limited to the following: chlorides, other halides, nitrates, nitrites, hydroxides, oxides, oxalates, acetates (OAc) and amines, while halide-free salts are preferred, and chloride-free salts are more preferred. Examples of palladium salts suitable for use in precursor solutions include PdCl ₂ , Na ₂ PdCl ₄ , Pd (NH ₃ ) ₂ (NO ₂ ) ₂ , Pd (NH ₃ ) ₄ (OH) ₂ , Pd (NH ₃ ) ₄ ( NO ₃ ) ₂ , Pd (NO ₃ ) ₂ , Pd (NH ₃ ) ₄ (OAc) ₂ , Pd (NH ₃ ) ₂ (OAc) ₂ , Pd (OAc) ₂ in KOH and / or NMe ₄ OH and / or NaOH, Pd (NH ₃ ) ₄ (HCO ₃ ) ₂ and palladium oxalate. Among the chloride containing palladium-containing precursors, Na ₂ PdCl ₄ is most preferred. Among the chloride-free salts of palladium-containing precursors, the following four are most preferred: Pd (NH ₃ ) ₄ (NO ₃ ) ₂ , Pd (NO ₃ ) ₂ , Pd (NH ₃ ) ₂ (NO ₂ ) ₂ , Pd (NH ₃ ) ₄ (OH) ₂ . Examples of gold salts suitable for use in precursor solutions include AuCl ₃ , HAuCl ₄ , NaAuCl ₄ , KAuO ₂ , NaAuO ₂ , NMe ₄ AuO ₂ , Au (OAc) ₃ in KOH and / or NMe ₄ OH, as well as HAu ( NO ₃ ) ₄ in nitric acid, with KAuO _{2 being the} most preferred among the chloride-free gold-containing precursors. Examples of rhodium salts suitable for use in precursor solutions include RhCl ₃ , Rh (OAc) ₃ and Rh (NO ₃ ) ₂ . Similar salts can also be selected for the third catalyst components described above.

In addition, more than one salt may be used in a particular precursor solution. For example, in a single precursor solution, the palladium salt can be combined with a gold salt, or two different palladium salts can be combined with each other. Precursor solutions can usually be obtained by dissolving selected salts or salts in water, in the presence or absence of solubility modifiers, such as acids, bases or other solvents. Other non-aqueous solvents may also be suitable.

Precursor solutions can impregnate carrier material simultaneously (e.g., co-impregnation) or sequentially, and impregnation can be carried out using one or more precursor solutions. In the case of three or more catalytic components, it is possible to use a combination of simultaneous and sequential impregnation. For example, palladium and rhodium can be impregnated using a single precursor solution (called co-impregnation), followed by impregnation with a solution of a gold-containing precursor. In addition, the carrier material can be impregnated with the catalytic component in several stages so that each time a part of the catalytic component is brought into contact. For example, one suitable protocol may include impregnation using Pd followed by impregnation using Au, followed by impregnation again using Au.

The procedure for impregnating carrier material with solutions of precursors is not critical; although there may be some advantages in certain orders, as discussed further in relation to the calcination step. Preferably, the carrier material is first impregnated with a palladium-containing catalyst component, with gold impregnated after palladium or the last. Rhodium or another third catalytic component, if used, can be impregnated with palladium, together with gold or just one. In addition, the support material can be impregnated several times with the same catalyst component. For example, you can first bring into contact a portion of all the gold contained in the catalyst, and then enter into contact the second part of gold. In the interval between the stages in which gold is brought into contact with the material of the carrier, one or more other stages can be carried out, for example, calcination, reduction and / or fixation.

The effect may be exerted by the acid-base profile of the precursor solutions, regardless of whether co-impregnation or sequential impregnation is used. Thus, at the stage of joint impregnation, only precursor solutions characterized by a similar acid-base profile should be shared; this will exclude any acid-base reactions that may poison the solutions of the precursors.

In the case of the impregnation step, the volume of the precursor solution is selected so that it corresponds to a value in the range from about 85% to about 110% of the pore volume of the carrier material. Preferred are volumes in the range of from about 95% to about 100% of the pore volume of the carrier material, and more preferably, from about 98% to about 99% of the pore volume.

Typically, the precursor solution is added to the carrier material, and the carrier material is allowed to absorb the precursor solution. This can be accomplished by droplet administration until essentially the initial moisture content of the carrier material is reached. Alternatively, the carrier material may be placed in aliquots of the precursor solution or periodically placed in the precursor solution. To ensure reliable contact between the carrier material and the precursor solution, it is possible to use a rotary dive apparatus or other auxiliary apparatus. In addition, it is possible to use a spray device so that the precursor solution is sprayed through the nozzle onto the carrier material where it is absorbed. To remove any excess liquid that has not been absorbed into the carrier material, or to dry the carrier material after impregnation, it is optionally possible to use decantation, heating, or reduced pressure.

In the case of the impregnation step, the volume of the precursor solution is chosen so that it corresponds to a value in the range from about 85% to about 110% of the pore volume of the carrier material. Preferred are volumes from about 95% to about 100% of the pore volume of the carrier material, and more preferably from about 98% to about 99% of the pore volume.

Typically, the precursor solution is added to the carrier material, and the carrier material is allowed to absorb the precursor solution. This can be accomplished by droplet administration until essentially the initial moisture content of the carrier material is reached. Alternatively, the carrier material may be placed in aliquots of the precursor solution or periodically placed in the precursor solution. To ensure reliable contact between the carrier material and the precursor solution, it is possible to use a rotary dive apparatus or other auxiliary apparatus. In addition, it is possible to use a spray device so that the precursor solution is sprayed through the nozzle onto the carrier material where it is absorbed. To remove any excess liquid that has not been absorbed into the carrier material, or to dry the carrier material after impregnation, it is optionally possible to use decantation, heating, or reduced pressure.

In order to avoid the stage of fixation, however, while obtaining a catalyst with an active zone on the surface, other contacting techniques can be used. For example, the catalyst components can be brought into contact with the support material using a chemical vapor deposition method such as described in US 2001/0048970, which is incorporated herein by reference. In addition, coating by a spraying method or otherwise layering a previously uniformly impregnated carrier material as the outer layer on the inner layer effectively results in a catalyst with a core on the surface, which can be described as a layered carrier material. In yet another methodology, the preparation of catalysts with a core on the surface allows the use of organometallic precursors of catalyst components, especially with regard to gold, as described in US Pat. No. 5,700,753, which is incorporated herein by reference.

To obtain catalysts with a core on the surface, a technique for physically forming a surface shell may also be suitable. In this case, the precursor solution can be sprayed onto the heated carrier material or onto the laminate of the carrier, where the solvent of the precursor solution is vaporized by contact with the heated carrier material, thereby precipitating the catalyst components in the surface shell on the carrier material. Preferably, temperatures in the range of about 40 to 140 ° C can be used. The thickness of the surface shell can be adjusted by selecting the temperature of the carrier material and the flow rate of the solution through the spray nozzle. For example, at temperatures exceeding approximately 100 ° C, a relatively thin surface shell is formed. In the case of the use of chloride-free precursors, this embodiment may be particularly suitable for helping to improve the formation of the surface shell on the support material.

The person skilled in the relevant field should understand that a combination of the steps of contacting may be a suitable way to obtain the contacted carrier material.

Stage of fixation

It may be desirable to convert at least a portion of the catalytic components on the contacted carrier material from a water soluble form to a water insoluble form. Such a stage may be called a fixation stage. It can be carried out by applying a fixing substance (for example, a dispersion in a liquid, such as a solution) on the impregnated carrier material, which will lead to the deposition of at least part of the catalytic components. This fixation step facilitates the preparation of a catalyst with a core on the surface, but it is not necessary for the preparation of catalysts with a core on the surface.

Any suitable fixing agent may be used, with hydroxides (e.g., alkali metal hydroxides), silicates, borates, carbonates and bicarbonates in aqueous solutions being preferred. A preferred fixing agent is NaOH. Fixation can be accomplished by adding a fixing agent to the support material before, during, or after the precursor solutions impregnate the support material. Typically, the fixing agent is used after the contacting step so that the contacted carrier material can be impregnated with the fixing agent solution for a period of time ranging from about 1 to about 24 hours. The exact time depends on the combination of the precursor solution and the fixing agent. Similar to the impregnation step, the fixation step can advantageously use an auxiliary device, such as a spin diving apparatus, described in US Pat. No. 5,332,710, which is incorporated herein by reference.

The fixation stage can be carried out in the form of one or more stages, called joint fixation or separate fixation. In the case of joint fixation, after all the appropriate precursor solutions have been brought into contact with the carrier material, one or more volumes of a fixing substance solution are applied to the carrier material brought into contact, regardless of whether the contact was made by using one or several solutions of precursors. For example, fixing after sequential impregnation with a solution of a palladium-containing precursor, a solution of a gold-containing precursor and a solution of a rhodium-containing precursor will be a joint fixation, as well as fixing after co-impregnation with a solution of a palladium / rhodium-containing precursor, followed by impregnation with a solution of a gold-containing precursor. An example of joint fixation can be found in US patent No. 5314888, which is incorporated herein by reference.

On the other hand, separate fixation will include applying a fixative solution during or after each impregnation with a precursor solution. For example, the following protocols will be a separate fixation: a) impregnation with palladium followed by fixation with further impregnation with gold followed by fixation; or b) co-impregnation with palladium and rhodium followed by fixation followed by impregnation with gold followed by fixation. In the interval between fixation and subsequent impregnation, any excess liquid can be removed and the carrier material dried, although this is not necessary. An example of separate fixation can be found in US patent No. 6034030, which is incorporated herein by reference.

In yet another embodiment, the fixation step and the contacting step are carried out simultaneously, one example of which is described in US Pat. No. 4,048,096, which is incorporated herein by reference. For example, simultaneous fixation can be: impregnation with palladium followed by fixation with further impregnation with gold and a fixing substance. In the modification of this embodiment, the fixation for the catalytic component can be carried out twice. The catalytic component can be partially fixed when it is brought into contact with the material of the carrier (what is called "preliminary fixation"), followed by an additional final fixation. For example, impregnation with palladium followed by impregnation with gold and a preliminary fixation substance with further fixation by a final fixation substance. This technique can be used to facilitate the formation of a type of core-type catalyst, as opposed to a core-type catalyst throughout the material.

In yet another embodiment, particularly suitable for use with chloride-free precursors, the support material is pretreated with a fixing agent to control the properties of the support material. In this embodiment, the support material is first impregnated with a solution of either an acid or a base, usually metal-free. After drying, the support material is impregnated with a precursor solution that has the opposite acidity / alkalinity compared to the dried support material. The subsequent acid-base reaction leads to the formation on the support material of a surface shell of catalytic components. For example, nitric acid can be used to pretreat the support material, which in turn is impregnated with a solution of a basic precursor, such as Pd (OH) ₂ or Au (OH) ₃ . This production technique can be considered as using the fixation step followed by the contacting step.

The concentration of the fixing substance in the solution usually corresponds to a molar excess in comparison with the amount of catalytic components impregnated on the support material. The amount of fixing substance should be in the range from about 1.0 to about 2.0, preferably from about 1.1 to about 1.8 times in comparison with the amount required to react with catalytically active cations, present in water soluble salt. In one embodiment, the use of a high atomic or mass ratio of Au / Pd, an increased molar excess of hydroxide ion leads to improved selectivity for CO ₂ and activity in the resulting catalyst.

The volume of the supplied solution of the fixing substance in the General case should be an amount sufficient to cover all available free surfaces of the impregnated carrier material. This can be done, for example, by introducing a volume that exceeds the pore volume of the carrier material introduced into the contact.

The combination of the stages of impregnation and fixation can lead to a catalyst of the type with an active zone on the surface. But the use of halide-free precursor solutions also makes it possible to obtain a catalyst with a core on the surface with the optional exception of the fixation step. In the absence of a chloride-containing precursor, the washing step discussed below can be dispensed with. In addition, the method may not include the stage of fixing the catalytic components, which in other cases would be necessary for successful passage through the washing stage. Since no washing step is required, the catalyst components do not need to be fixed in order to successfully pass through the washing step. The subsequent steps in the catalyst preparation process do not require fixing the catalytic components, and thus, the remainder of the step can be carried out without additional preparatory steps. In General, the use of chloride-free precursors makes it possible to create a method for producing a catalyst or procatalyst, which does not include washing stages, which, thus, reduces the number of stages required to obtain a catalyst, and eliminates the need for disposal of chloride-containing waste.

Washing stage

In particular, if solutions of precursors containing halides are used, and if desired, with other application options, after the fixing step, the supported material can be washed with a fixed material to be washed to remove any residual amount of halides on the carrier or otherwise treated to eliminate the potential negative effect of the contaminant on carrier material. The washing step involved rinsing the fixed carrier material in water, preferably deionized water. Rinsing can be carried out in batch or continuous mode. Rinsing at room temperature should continue until the effluent washes had a halide content of less than about 1000 ppm, and more preferably, until the final product gave a negative test using silver nitrate. The washing step can be carried out after or during the recovery step, discussed below, but preferably it is carried out before it. As discussed above, the use of halide-free precursor solutions makes it possible to eliminate the washing step.

Calcination stage

After at least one catalytic component is brought into contact with the support material, a calcination step can be carried out. The calcination step is usually carried out before the reduction step and after the fixation step (if such a step is used), but it may also be present in other parts of the process. In yet another embodiment, the calcination step is carried out after the reduction step. The calcination step involves heating the support material in a non-reducing atmosphere (i.e., oxidizing or inert). During calcination, the catalytic components on the support material decompose at least partially, turning from their salts into a mixture of their oxide form and free metal form.

For example, the calcination step is carried out at a temperature in the range of from about 100 ° C to about 700 ° C, preferably from about 200 ° C to about 500 ° C. Non-reducing gases used for calcination may include one or more inert or oxidizing gases, such as helium, nitrogen, argon, neon, nitrogen oxides, oxygen, air, carbon dioxide, combinations thereof and the like. In one embodiment, the calcination step is carried out in an atmosphere of substantially pure nitrogen, oxygen, air, or combinations thereof. Calcination times may vary, but preferably they are in the range of about 1 to 5 hours. The degree of decomposition of the salts of the catalytic components depends on the temperature used and the length of time during which the impregnated catalyst will be calcined, and it can be monitored by monitoring the volatile decomposition products.

One or more calcination steps can be carried out in such a way that, at any point after at least one catalytic component has been brought into contact with the support material, it can be calcined. Preferably, the last calcination step is carried out before the gold-containing catalyst component is brought into contact with the zirconia-based support material. Alternatively, the calcination of the gold-containing zirconia-based support material is carried out at temperatures lower than about 300 ° C. Due to the fact that the calcination of the gold-containing material of the carrier based on zirconium dioxide is not carried out at temperatures exceeding approximately 300 ° C, the risk of a negative effect on the selectivity with respect to the production of CO ₂ from the resulting catalyst is reduced.

Exemplary protocols including a calcination step include: a) impregnation with palladium followed by calcination followed by impregnation with gold; b) co-impregnation with palladium and rhodium followed by calcination followed by impregnation using Au; c) impregnation with palladium followed by calcination followed by impregnation with rhodium followed by calcination with further impregnation with gold; or d) impregnation with palladium and rhodium followed by impregnation with gold followed by calcination.

Recovery stage

Another step, generally used in the present invention, is at least to partially convert any residual catalyst components from a salt or oxide form into a catalytically active state, such as a result of a reduction step. It is usually carried out by exposing the salts or oxides to a reducing agent, examples of which include ammonia, carbon monoxide, hydrogen, hydrocarbons, olefins, aldehydes, alcohols, hydrazine, primary amines, carboxylic acids, carboxylic acid salts, carboxylic acid esters and combinations thereof. Preferred reducing agents are hydrogen, ethylene, propylene, hydrazine in an alkaline medium and formaldehyde in an alkaline medium, and combinations thereof, with ethylene and hydrogen mixed with inert gases being particularly preferred. Although it is preferable to recover using a gaseous medium, it is also possible to use a reduction step carried out using a liquid medium (for example, using a reducing solution). The temperature selected for recovery may range from ambient temperature up to about 550 ° C. Recovery times will usually vary from about 1 to about 5 hours.

Since the method used to reduce the catalyst components may affect the characteristics of the final catalyst, the conditions used for the reduction may vary depending on whether high activity, high selectivity or a certain balance of these properties is desired.

In one embodiment, palladium is contacted with the support material, fixed and reduced before gold is contacted and reduced, as described in US Pat. Nos. 6,460,693, 6,015,769 and related patents, all of which are incorporated herein by reference. .

Exemplary protocols including a reduction step include: a) impregnation with palladium followed by optional calcination followed by impregnation with gold followed by reduction; b) co-impregnation with palladium and gold, followed by optional calcination with further reduction; or c) impregnation with palladium followed by optional calcination followed by reduction followed by impregnation with gold.

Modification Stage

Typically, after the reduction step and before using the catalyst, the modification step is desirable. While the catalyst can be used after the modification step, this step results in some favorable results, including an extension of the operational life of the catalyst. The modification step is sometimes called the activation step, and can be carried out in accordance with normal practice. Namely, the reduced carrier material is brought into contact with a modifier, such as an alkali metal carboxylate and / or alkali metal hydroxide, before use. For this purpose, conventional alkali metal carboxylates are used, such as sodium, potassium, lithium and cesium salts of C _2-4 aliphatic carboxylic acids. The preferred activator in the production of VA is alkali metal acetate, with potassium acetate (KOAc) being most preferred.

The carrier material may optionally be impregnated with a modifier solution. After drying, the catalyst may contain, for example, from about 10 to about 70, preferably from about 20 to about 60 grams of modifier per liter of catalyst.

Methods for producing alkenylalkanoates

The present invention can be used to produce alkenyl alkanoates from alkene, alkanoic acid and an oxygen-containing gas in the presence of a catalyst. Preferred alkene feedstocks contain from two to four carbon atoms (e.g. ethylene, propylene and n-butene). Preferred alkanoic acid feedstocks used in the process of this invention for the production of alkenyl alkanoates contain from two to four carbon atoms (e.g., acetic, propionic and butyric acids). Preferred products in the process are VA, vinyl propionate, vinyl butyrate and allyl acetate. The most preferred starting materials are ethylene and acetic acid, with VA being the most preferred product. Thus, the present invention is suitable for use in the preparation of olefinic type unsaturated carboxylic acid esters from an olefinic type, carboxylic acid and oxygen unsaturation compound in the presence of a catalyst. Although the rest of the description of the invention discusses VA exclusively, it should be understood that the catalysts, the method for producing the catalysts and the production methods are equally applicable to other alkenyl alkanoates, and the description does not imply a limitation of the invention to VA.

If VA is obtained using the catalyst of the present invention, then a gas stream that contains ethylene, oxygen or air and acetic acid is passed through the catalyst. The composition of the gas stream can vary widely, taking into account the presence of a flammability region for the product stream. For example, the molar ratio between ethylene and oxygen may be in the range of from about 80:20 to about 98: 2, the molar ratio between acetic acid and ethylene may be in the range of from about 100: 1 to about 1: 100, preferably from about 10 : 1 to 1:10, and most preferably, from about 1: 1 to about 1: 8. The gas stream may also contain gaseous alkali metal acetate and / or inert gases such as nitrogen, carbon dioxide and / or saturated hydrocarbons. Reaction temperatures that can be used are elevated temperatures, preferably temperatures in the range of about 125-220 ° C. The pressure used may be somewhat reduced pressure, normal pressure or increased pressure, preferably pressure up to about 20 atmospheres gauge pressure.

In addition to fixed-bed reactors, the methods for producing alkenyl alkanoates and the catalyst of the present invention can also be suitably used in other types of reaction, for example, in fluidized-bed reactors.

EXAMPLES

The following examples are provided for illustration only and are not intended to be limiting. Amounts of solvents and reagents are approximate. The atomic ratio Au / Pd can be converted to the mass ratio Au / Pd and vice versa using the following equations: atomic ratio Au / Pd = 0.54 * (mass ratio Au / Pd) and mass ratio Au / Pd = 1.85 (atomic ratio Au / Pd). Recovery can be abbreviated as “R” followed by the temperature in ° C at which recovery is carried out. Similarly, calcination can be abbreviated as “C” followed by the temperature in ° C at which the calcination is carried out, while the drying step can be abbreviated as “dry”.

The catalyst from examples 1-11 can be obtained as described in the example, and tested in accordance with the following procedure, where the catalyst from examples 1-7 can be matched to each other, and the catalyst from examples 8- can be matched to each other eleven. Results are shown if available.

The catalysts of the examples were tested to determine their activity and selectivity for various by-products in the production of vinyl acetate as a result of the reaction between ethylene, oxygen and acetic acid. To achieve this, approximately 60 ml of the catalyst prepared as described was placed in a stainless steel basket at a temperature that could be measured with a thermocouple both at the top and bottom of the basket. The basket was placed in a Berty type Recycling Tank with Continuous Stirring, and was held at a temperature with an electrically heated jacket to achieve an oxygen conversion of approximately 45%. A gas mixture formed from approximately 50 normal liters (measured at normal temperature and pressure) of ethylene, approximately 10 normal liters of oxygen, approximately 49 normal liters of nitrogen, approximately 50 g of acetic acid and approximately 4 mg of potassium acetate, at a pressure of approximately 12 atmospheres , passed through a basket, and the catalyst was kept under these reaction conditions for at least 16 hours before a two-hour run of the system, after which the reaction was completed . Product analysis was performed using real-time gas chromatography analysis in combination with offline analysis of liquid products, carried out by condensing the product stream at approximately 10 ° C, ensuring optimal analysis of the final products in the form of carbon dioxide (CO ₂ ), heavy ends (HE) and ethyl acetate (EtOAc), where these results can be used to calculate the percentage selectivity (selectivity for obtaining CO ₂₎ in respect of receipt of data aterialov for each example. The relative activity in the reaction, expressed as the coefficient of activity (activity), can be calculated on a computer using a series of equations that establish a correlation between the coefficient of activity and the temperature of the catalyst (during the reaction), the degree of oxygen conversion, and a series of kinetic parameters for reactions that have place during VA synthesis. In a more general case, the activity coefficient is usually inversely proportional to the temperature necessary to achieve a constant degree of oxygen conversion.

Examples of rhodium catalyst

Example 1

A support material containing metallic palladium and rhodium was prepared as follows: a support material of 250 ml consisting of Sud Chemie KA-160 silica spheres having a nominal diameter of 7 mm, a density of approximately 0.569 g / ml, and an absorption capacity of approximately equal to 0.568 g H ₂ O / g support, a surface area in the range from about 160 to 175 m ² / g and a pore volume of about 0.68 ml / g, was first impregnated by incipient wetness with 82.5 ml vodnog solution of sodium tetrachloropalladium (II) (Na ₂ PdCl ₄₎ and trigidrita rhodium chloride (RhCl ₃ • 3H ₂ O), which was sufficient to provide about 7 grams of elemental palladium and about 0.29 grams of elemental rhodium per liter of catalyst. The carrier was shaken in the solution for 5 minutes to ensure complete absorption of the solution. After that, palladium and rhodium were fixed on the carrier in the form of palladium (II) and rhodium (III) hydroxides using immersion with rotation for 2.5 hours at about 5 rpm during the operation of contacting the treated carrier with 283 ml of aqueous a solution of sodium hydroxide obtained from a solution of NaOH / H ₂ O with a concentration of 50% (wt./wt.) in an amount of 120% of the amount necessary for the conversion of palladium and rhodium into their hydroxides. The solution from the treated carrier was drained, and the carrier was then washed with deionized water and dried at 100 ° C. in a fluidized bed dryer for 1.2 hours. Then, the support material containing palladium and rhodium hydroxides was impregnated with an aqueous solution (81 ml) containing 1.24 g of Au from NaAuCl ₄ and 2.71 g of a 50% NaOH solution (1.8 equivalent to Au), at using the method with reaching the initial humidity. The NaOH treated pellets were allowed to stand overnight to allow the Au salt to precipitate to form an insoluble hydroxide. The granules were thoroughly washed with deionized water (~ 5 hours) to remove chloride ions and then dried at 100 ° C in a fluidized bed dryer for 1.2 hours. After this, the palladium, rhodium, and gold-containing support was calcined at 400 ° C. for 2 hours in air, and then allowed to cool naturally to room temperature. Palladium, rhodium and gold were recovered by bringing the support into contact with C ₂ H ₄ (1% in nitrogen) in the vapor phase at 150 ° C for 5 hours. In conclusion, the catalyst was impregnated to an initial moisture content using an aqueous solution of 10 g of potassium acetate in 81 ml of H ₂ O and dried in a fluid bed dryer at 100 ° C. for 1.2 hours.

Example 2

A support material using palladium and rhodium hydroxides was prepared as described in Example 1. After that, the palladium and rhodium-containing support was calcined at 400 ° C. for 2 hours in air, and then allowed to cool naturally to room temperature. Then, the calcined support material containing palladium and rhodium hydroxides was impregnated with an aqueous solution (81 ml) containing 1.24 g of Au from NaAuCl ₄ and 2.71 g of a 50% NaOH solution (1.8 equivalent to Au) when using the method with reaching the initial humidity. The NaOH treated pellets were allowed to stand overnight to allow the Au salt to precipitate to form an insoluble hydroxide. The granules were thoroughly washed with deionized water (~ 5 hours) to remove chloride ions and then dried at 100 ° C in a fluidized bed dryer for 1.2 hours. Then, palladium, rhodium and gold were recovered by bringing the support into contact with C ₂ H ₄ (1% in nitrogen) in the vapor phase at 150 ° C for 5 hours. In conclusion, the catalyst was impregnated to an initial moisture content using an aqueous solution of 10 g of potassium acetate in 81 ml of H ₂ O and dried in a fluid bed dryer at 100 ° C. for 1.2 hours.

Example 3

The carrier material containing palladium and rhodium hydroxides was prepared as described in Example 1. After that, the palladium and rhodium-containing support was calcined at 400 ° C. for 2 hours in air, and then allowed to naturally cool to room temperature. The calcined support material containing palladium and rhodium hydroxides was then reduced by contacting the support with C ₂ H ₄ (1% in nitrogen) in the vapor phase at 150 ° C. for 5 hours. After that, the carrier containing palladium and rhodium metal was impregnated with an aqueous solution (81 ml) containing 1.24 g of Au from NaAuCl ₄ and 2.71 g of a 50% NaOH solution (1.8 equivalent to Au), at using the method with reaching the initial humidity. The NaOH treated pellets were allowed to stand overnight to allow the Au salt to precipitate to form an insoluble hydroxide. The granules were thoroughly washed with deionized water (~ 5 hours) to remove chloride ions and then dried at 100 ° C in a fluidized bed dryer for 1.2 hours. Then, palladium, rhodium and gold were recovered by bringing the support into contact with C ₂ H ₄ (1% in nitrogen) in the vapor phase at 150 ° C for 5 hours. In conclusion, the catalyst was impregnated to an initial moisture content using an aqueous solution of 10 g of potassium acetate in 81 ml of H ₂ O and dried in a fluid bed dryer at 100 ° C. for 1.2 hours.

Example 4

The carrier material containing palladium and rhodium hydroxides was prepared as described in Example 1. After that, the palladium and rhodium-containing support was calcined at 400 ° C. for 2 hours in air, and then allowed to naturally cool to room temperature. The calcined support material containing palladium and rhodium hydroxides was then reduced by contacting the support with C ₂ H ₄ (1% in nitrogen) in the vapor phase at 150 ° C. for 5 hours. After that, the carrier containing metallic palladium and rhodium was impregnated with an aqueous solution (81 ml) containing 1.1 g of Au from KAuO ₂ , using the method with reaching the initial humidity. The granules were then dried at 100 ° C. in a fluid bed dryer for 1.2 hours. Then, palladium, rhodium and gold were recovered by bringing the support into contact with C ₂ H ₄ (1% in nitrogen) in the vapor phase at 150 ° C for 5 hours. In conclusion, the catalyst was impregnated to an initial moisture content using an aqueous solution of 10 g of potassium acetate in 81 ml of H ₂ O and dried in a fluid bed dryer at 100 ° C. for 1.2 hours.

Example 5

The carrier material containing palladium and rhodium hydroxides was prepared as described in Example 1. After that, the palladium and rhodium-containing support was calcined at 400 ° C. for 2 hours in air, and then allowed to naturally cool to room temperature. Then, the calcined support material containing palladium and rhodium hydroxides was impregnated with an aqueous solution (81 ml) containing 1.1 g of Au from KAuO ₂ using a method to achieve initial moisture. The granules were then dried at 100 ° C. in a fluid bed dryer for 1.2 hours. Then, palladium, rhodium and gold were recovered by bringing the support into contact with C ₂ H ₄ (1% in nitrogen) in the vapor phase at 150 ° C for 5 hours. In conclusion, the catalyst was impregnated to an initial moisture content using an aqueous solution of 10 g of potassium acetate in 81 ml of H ₂ O and dried in a fluid bed dryer at 100 ° C. for 1.2 hours.

Example 6

The carrier material containing palladium and rhodium hydroxides was prepared as described in Example 1. After that, the palladium and rhodium-containing support was calcined at 400 ° C. for 2 hours in air, and then allowed to naturally cool to room temperature. The calcined support material containing palladium and rhodium hydroxides was then reduced by contacting the support with C ₂ H ₄ (1% in nitrogen) in the vapor phase at 150 ° C. for 5 hours. After that, the carrier containing metallic palladium and rhodium was impregnated with an aqueous solution (81 ml) containing 1.1 g of Au from KAuO ₂ and 10 g of potassium acetate, using the method to achieve initial humidity. The granules were then dried at 100 ° C. in a fluid bed dryer for 1.2 hours.

Example 6-1

The carrier material containing palladium and rhodium hydroxides is prepared as described in Example 1. After that, the palladium and rhodium-containing support is calcined at 400 ° C. for 2 hours in air, and then allowed to cool naturally to room temperature. Then, the calcined support material containing palladium and rhodium hydroxides is reduced by contacting the support with C ₂ H ₄ (1% in nitrogen) in the vapor phase at 150 ° C. for 5 hours. After that, the carrier containing metallic palladium and rhodium is impregnated with an aqueous solution (85 ml) containing 1.2 g of Au from NMe ₄ AuO ₂ and 9 g of ammonium acetate, using the method to achieve the initial moisture content. The granules are then dried at 100 ° C. in a fluid bed dryer for 1.2 hours.

Example 6-2

The carrier material containing palladium and rhodium hydroxides is prepared as described in Example 1. After that, the palladium and rhodium-containing support is calcined at 400 ° C. for 2 hours in air, and then allowed to cool naturally to room temperature. Then, the calcined support material containing palladium and rhodium hydroxides is reduced by contacting the support with C ₂ H ₄ (1% in nitrogen) in the vapor phase at 150 ° C. for 5 hours. After that, the carrier containing metallic palladium and rhodium is impregnated with an aqueous solution (82 ml) containing 0.98 g of Au from HAu (NO ₃ ) ₄ and nitric acid, using the method to achieve initial humidity. The granules are then dried at 100 ° C. in a fluid bed dryer for 1.2 hours.

Example 7 (comparative catalyst)

The carrier material containing palladium metal was prepared as follows: a carrier material in an amount of 250 ml, consisting of Sud Chemie KA-160 silica spheres characterized by a nominal diameter of 7 mm, a density of approximately 0.569 g / ml, and an absorption capacity of approximately 0.568 g of H ₂ O / g of carrier, with a specific surface area in the range of about 160 to 175 m ² / g and a pore volume of about 0.68 ml / g, was first impregnated to reach the initial moisture content using 82.5 ml of an aqueous solution and sodium tetrachloropalladium (II) (Na ₂ PdCl ₄ ), which was sufficient to obtain approximately 7 grams of elemental palladium per liter of catalyst. The carrier was shaken in the solution for 5 minutes to ensure complete absorption of the solution. After that, the palladium was fixed on the carrier in the form of palladium (II) hydroxides using immersion with rotation for 2.5 hours at about 5 rpm during the operation of introducing the treated carrier into contact with 283 ml of an aqueous solution of sodium hydroxide obtained from the solution NaOH / H ₂ O with a concentration of 50% (w / w) in an amount of 110% of the amount necessary for the conversion of palladium to its hydroxide. The solution from the treated carrier was drained, and the carrier was then washed with deionized water and dried at 100 ° C. in a fluidized bed dryer for 1.2 hours. Then, the support material containing palladium hydroxide was impregnated with an aqueous solution (81 ml) containing 1.24 g of Au from NaAuCl ₄ and 2.71 g of a 50% NaOH solution (1.8 equivalent to Au) using the method with achievement of initial humidity. The NaOH treated pellets were allowed to stand overnight to allow the Au salt to precipitate to form an insoluble hydroxide. The granules were thoroughly washed with deionized water (~ 5 hours) to remove chloride ions and then dried at 100 ° C in a fluidized bed dryer for 1.2 hours. After that, the palladium and gold-containing support was restored by bringing the support into contact with C ₂ H ₄ (1% in nitrogen) in the vapor phase at 150 ° C for 5 hours. In conclusion, the catalyst was impregnated to an initial moisture content using an aqueous solution of 10 g of potassium acetate in 81 ml of H ₂ O and dried in a fluid bed dryer at 100 ° C. for 1.2 hours. Table 1 shows a comparison of selectivity for CO ₂ and activity for the catalyst of Examples 1 and 7.

Table 1 Selectivity for CO ₂ Activity Example 1 9.89 2,32 Example 7 (comparative catalyst) 11.13 2,36

Layered Carrier Examples

Example 8

40 g of ZrO ₂ (RC-100, available from DKK) were calcined at 650 ° C. for 3 hours. The resulting material was characterized by a specific surface area of 38 m ² / g according to the BET measurements. The material was ground in a ball mill for 6 hours in the presence of 120 ml of deionized water. The sol was mixed with 22.5 g of a binder in the form of zirconium acetate supplied by DKK (ZA-20) and sprayed onto 55 g of KA-160 bentonite spheres with an outer diameter of ~ 7.5 mm. The coated granules were calcined for 3 hours at 600 ° C. Observation through a microscope indicated the formation of a uniform surface shell with a thickness of 250 μm.

Example 9

20 g of ZrO ₂ (XZ16075, specific surface area of 55 m ² / g according to the BET method) was impregnated with a Pd (NO ₃ ) ₂ (Aldrich) solution to obtain a Pd content of 39 mg / g ZrO ₂ . The impregnated material was dried and calcined at 450 ° C for 4 hours. The material was ground in a ball mill for 4 hours in the presence of 60 ml of deionized water, mixed with 11 g of a binder (ZA-20) and sprayed onto 30 g of spheres made of bentonite KA-160. The granules were calcined for 3 hours at 450 ° C. This technique as a result led to the formation of a strong uniform surface shell with a thickness of 160 μm.

Example 10

The granules from Example 8 were impregnated with a potassium acetate solution to obtain a fill value of 40 mg KOAc / ml KA-160, dried and calcined at 300 ° C for 4 hours. After that, a solution containing 9.4 mM Pd (from Pd (NH ₃ ) ₄ (OH) ₂ supplied by Heraeus) and 4.7 mM Au (from a solution with a concentration of 1 M obtained by dissolving Au ( OH) ₃ “Alfa” in 1.6M KOH). The material was recovered using a mixture of: 5% H ₂ , 95% N ₂ at 200 ° C for 4 hours. The granules were crushed and tested in a fixed-bed microreactor under the conditions described in the experimental section. The selectivity values with respect to the production of CO ₂ ~ 6% and the degree of oxygen conversion of 45% were achieved.

Example 11 (comparative catalyst)

In this case, the same catalyst used as the comparative catalyst was used as that obtained in Example 7. Table 2 shows a comparison of the selectivity for producing CO ₂ and the activity for the catalyst from Examples 9-11.

table 2 Selectivity for CO ₂ Activity Example 9 9.33 2.08 Example 10 9.03 1,69 Example 11 (comparative catalyst) 11.13 2,36

Examples of carrier material based on zirconia and chloride-free precursors

The following general procedure was used for this set of examples. Catalysts containing zirconia-based support material were prepared as follows: various shaped catalyst supports were crushed and sieved. Zirconia-based support materials were supplied from NorPro (XZ16052 and XZ16075), DKK and MEI. Silicon dioxide-based carrier materials were supplied from Degussa and Sud Chemie. A sieve fraction of 180-425 μm was impregnated (either simultaneously or sequentially with an intermediate stage of drying at 110 ° C and optionally with an intermediate stage of calcination) until the initial humidity was reached using a solution of the Pd and Au precursor, optionally calcined in air, and restored using formation gas 5% H ₂ / N ₂ was subjected to subsequent impregnation with a KOAc solution, dried at 100 ° C in an N ₂ atmosphere, and tested in an 8 × 6 multi-channel reactor with a fixed catalyst bed. A solution of Au (OH) ₃ in KOH was used as an Au precursor. Aqueous solutions of Pd (NH ₃ ) ₄ (OH) ₂ , Pd (NH ₃ ) ₂ (NO ₂ ) ₂ , Pd (NH ₃ ) ₄ (NO ₃ ) ₂ and Pd (NO ₃ ) _{2 were} used as Pd precursors.

A comparative catalyst containing silica-based support material was prepared as follows. A support material containing metallic palladium and rhodium was prepared as follows: a support material of 250 ml consisting of Sud Chemie KA-160 silica spheres having a nominal diameter of 7 mm, a density of approximately 0.569 g / ml, and an absorption capacity of approximately equal to 0.568 g H ₂ O / g support, a surface area in the range from about 160 to 175 m ² / g and a pore volume of about 0.68 ml / g, was first impregnated by incipient wetness with 82.5 ml vodnog solution of sodium tetrachloropalladium (II) (Na ₂ PdCl _4), which was sufficient to provide about 7 grams of elemental palladium per liter of catalyst. The carrier was shaken in the solution for 5 minutes to ensure complete absorption of the solution. After that, the palladium was fixed on the carrier in the form of palladium (II) hydroxides using immersion with rotation for 2.5 hours at about 5 rpm during the operation of introducing the treated carrier into contact with 283 ml of an aqueous solution of sodium hydroxide obtained from the solution NaOH / H ₂ O with a concentration of 50% (w / w) in an amount of 110% of the amount necessary for the conversion of palladium to its hydroxide. The solution from the treated carrier was drained, and the carrier was then washed with deionized water and dried at 100 ° C. in a fluidized bed dryer for 1.2 hours. Then, the support material containing palladium hydroxide was impregnated with an aqueous solution (81 ml) containing 1.24 g of Au from NaAuCl ₄ and 2.71 g of a 50% NaOH solution (1.8 equivalent to Au) using the method with achievement of initial humidity. The NaOH treated pellets were allowed to stand overnight to allow the Au salt to precipitate to form an insoluble hydroxide. The granules were thoroughly washed with deionized water (~ 5 hours) to remove chloride ions and then dried at 100 ° C in a fluidized bed dryer for 1.2 hours. After that, the palladium and gold-containing support was restored by bringing the support into contact with C ₂ H ₄ (1% in nitrogen) in the vapor phase at 150 ° C for 5 hours. In conclusion, the catalyst was impregnated to an initial moisture content using an aqueous solution of 10 g of potassium acetate in 81 ml of H ₂ O and dried in a fluid bed dryer at 100 ° C. for 1.2 hours. Before testing, the catalyst was crushed and sieved. A sieve fraction with a size range of 180-425 μm was used.

Catalyst libraries were developed with arrays of 8 rows × 6 columns of glass containers, and a rack with 36 glass containers was mounted on a shaking and stirring apparatus, and stirring was carried out while dosing metal precursor solutions using Cavro ™ liquid dispensing robots. 0.4 ml of the carrier was used for each element of the library, for synthesis in a glass vessel, and also loaded into each reaction vessel.

The degree of administration of KOAc was reported as grams of KOAc per liter of catalyst volume or as micromoles of KOAc per 0.4 ml of support. To describe the degree of introduction of Au, the relative atomic ratio between Au and Pd was given as Au / Pd. The degree of Pd administration was indicated as mg Pd per 0.4 ml of vehicle volume (i.e., the absolute amount of Pd in the reaction vessel).

The test report used a linear increase in temperature from 145 ° C to 165 ° C in increments of 5 ° C under conditions of a fixed bulk velocity of 175% (at 1.5 mg Pd per 0.4 ml of vehicle). 100% space velocity was determined as the following flows: 5.75 standard cubic centimeter of nitrogen per minute, 0.94 standard cubic centimeter of oxygen per minute, 5.94 standard cubic centimeter of ethylene per minute and 5.38 microliters of acetic acid in minute through each of the 48 containers with catalysts (of which all were characterized by an inner diameter of approximately equal to 4 mm). The graphical dependence of the selectivity in relation to the production of CO ₂ on the degree of conversion of oxygen was built, a straight line was selected that was consistent with the experimental data, and the selectivity in most cases for CO ₂ production at the degree of conversion of oxygen of 45%, presented in the following free operating tables, was calculated characteristics. The temperature was also given at an oxygen conversion of 45%, calculated from a linear increase in T (direct lines describing the dependence of selectivity in relation to the production of CO ₂ on the degree of oxygen conversion as a function of reaction temperature). The lower the calculated temperature, the higher the activity of the catalyst. The yield in grams per hour per unit volume of catalyst (STY; g VA obtained per ml of catalyst volume in one hour) at an oxygen conversion of 45% is a measure of the productivity of the catalyst.

Example 12

400 μl of carriers based on ZrO ₂ XZ16075 (55 m ² / g, without additional processing) and XZ16052 (preliminary calcination at 650 ° C / 2 hours to reduce the specific surface area to 42 m ² / g) were impregnated using 3 different Pd solutions , until the initial humidity was reached, dried at 110 ° C for 5 hours, impregnated using KAuO ₂ (mother solution containing 0.97 M Au), until the initial humidity was reached, dried at 110 ° C for 5 hours, restored at 350 ° C for 4 hours using gas reservoir 5% H ₂ / N _2, was subjected to follow it impregnation using KOAc and dried at 110 ° C for 5 hours. After that, Pd / Au / ZrO ₂ samples (surface shells) were diluted in a 1 / 9.3 ratio using a diluent for KA160 (with a preliminary introduction of 40 g / l KOAc), i.e. 43 μl of Pd-based surface shell was loaded into the reaction vessels / Au / ZrO ₂ and 357 μl of diluent (total fixed-bed volume 400 μl). The degree of Pd administration was 14 mg of Pd in 400 μl of the surface shell of ZrO ₂ (or 14 * 43/400 = 14 / 9.3 = 1.5 mg of Pd in the reaction vessel for all library elements). Pd precursors were Pd (NH ₃ ) ₂ (NO ₂ ) ₂ in columns 1 and 4, Pd (NH ₃ ) ₄ (OH) ₂ in columns 2 and 5, Pd (NH ₃ ) ₄ (NO ₃ ) ₂ in columns 3 and 6. Au / Pd = 0.3 in line 2 and line 5, Au / Pd = 0.6 in line 3, Au / Pd = 0.9 in line 4, line 6 and line 7. The degree of introduction of KOAs was 114 μmol in lines 2, 3, 5, and 147 μmol in lines 4, 6, 7. A silica-based comparative catalyst was loaded in line 1. The library was tested using a test protocol with ramping T at a fixed SV. The test results are summarized in table 3.

Table 3 Selectivity for CO ₂ Temperature at STY Cl-containing precursors on SiO ₂ 7.37 156.6 729 Pd (NH ₄ ) ₂ (OH) ₂ on ZrO ₂ 5.79 152.4 787 Pd (NH ₃ ) ₄ (NO ₃ ) ₂ on ZrO ₂ 5.90 152.3 783 Pd (NH ₃ ) ₂ (NO ₂ ) ₂ on ZrO ₂ 5.57 150.7 795 * Demonstrated data were obtained based on averaging for two atomic Au / Pd ratios (namely, 0.3 and 0.6) and for two different ZrO ₂ carriers.

Example 13

400 μl of ZrO ₂ -based carriers XZ16075 (55 m ² / g, no additional treatment) and XZ16052 (preliminary calcination at 650 ° C / 2 hours to reduce the specific surface area to 42 m ² / g) were impregnated using Pd (NH ₃ ) ₄ (OH) ₂ (mother liquor containing 1.117 M Pd), until the initial humidity was reached, calcined at 350 ° C for 4 hours in air, impregnated with KAuO ₂ (mother liquor containing 0.97 M Au), reaching the initial humidity, dried at 110 ° C for 5 hours, restored at 350 ° C for 4 hours using layers th gas 5% H ₂ / N _2, was subjected to the subsequent impregnation using KOAc and dried at 110 ° C for 5 hours. After that, Pd / Au / ZrO ₂ samples (surface shells) were diluted in a 1/12 ratio using a diluent for KA160 (with preliminary introduction of 40 g / L KOAc), i.e. 33.3 μl of Pd / Au / ZrO ₂ and 366.7 μl of diluent (total fixed bed volume 400 μl). The structure of the library and the compositions of the library elements were as follows: ZrO ₂ XZ16075 in columns 1-3 (left half of the library) and ZrO ₂ XZ16052 (650 ° C) in columns 4-6 (right half of the library). The degree of Pd administration was 18 mg of Pd in 400 μl of the ZrO ₂ surface coat (or 18 * 33/400 = 18/12 mg of Pd in the reaction vessel) in cell G2, column 3 (cells B3-G3), cell G5, column 6 (cells B6-G6); 10 mg Pd in 400 μl of the surface shell of ZrO ₂ (or 10 * 33/400 = 10/12 mg Pd in the reaction vessel) in column 1 (cells A1-G1) and column 4 (cells A4-G4); 14 mg of Pd in 400 μl of the surface coat of ZrO ₂ (or 14 * 33/400 = 14/12 mg of Pd in the reaction vessel) in column 2 (cells B2-F2) and column 5 (cells B5-F5). Au / Pd = 0.3 in line 2 and line 5, Au / Pd = 0.5 in line 3 and line 6, Au / Pd = 0.7 in line 4 and line 7 (excluding cells A1, A4, G2 , G5, where Au / Pd was 0.3). The degree of administration of KOAc was 114 μmol (with the exception of cells D3, G3, D6, G6, where the degree of administration of KOAc was 147 μmol). A comparative silica-based catalyst was loaded in line 1. The library was tested using a test protocol with ramping T at a fixed SV. The test results are summarized in table 4.

Table 4 Selectivity for CO ₂ Temperature at a degree of conversion of 45% STY Atomic ratio Au / Pd 0.3 0.5 0.7 0.3 0.5 0.7 0.3 0.5 0.7 Cl-containing precursors on SiO ₂ 6.98 - - 154.8 - - 742.8 - - ZrO ₂ : XZ16052 6.06 5.31 5.38 153.7 152.3 154.9 776.8 806.0 803.0 ZrO ₂ : XZ16075 6.18 5.62 5.71 147.5 151.0 154.4 773.8 791.6 790.3

Example 14

A ZrO ₂ -based carrier (available from NorPro, XZ16075, sieve fraction 180-425 μm, density 1.15 g / ml, pore volume 475 μl / g, specific surface area 55 m2 / g according to BET measurement) was impregnated with a solution Pd (NO ₃ ) ₂ precursor until the initial moisture content was reached, dried at 110 ° C, calcined at 250 ° C (columns 1-2), 350 ° C (columns 3-4), 450 ° C (columns 5-6) air, impregnated with a solution of KAuO ₂ (obtained by dissolving Au (OH) ₃ in KOH), dried at 110 ° C, restored at 350 ° C for 4 hours using formation gas 5% H ₂ / N ₂ and was subjected to subsequent impregnation with a solution of KOAc. The library had a KOAc gradient from 25 to 50 g / L in the area from line 2 to line 7. The degree of Pd administration was 1.5 mg Pd per 0.4 ml of vehicle. Two different degrees of administration of Au were chosen (Au / Pd = 0.5 in columns 1, 3, 5 and Au / Pd = 0.7 in columns 2, 4, 6). A silica-based comparative catalyst was loaded in line 1. The library was tested using a ramp test protocol with a fixed SV in the VA MCFB48 production reactor. The test results are summarized in table 5.

Table 5 Selectivity for CO ₂ Temperature at a degree of conversion of 45% STY Cl-containing precursors on SiO ₂ 7.21 154.7 734 Pd (NO ₃ ) ₂ on ZrO ₂ 6.10 145.3 775 * The demonstrated data were obtained on the basis of averaging for two atomic Au / Pd ratios (namely 0.5 and 0.7), at 40 g / L KOAc, calcining at 450 ° C and reducing at 350 ° C.

Example 15

ZrO ₂ -based carrier (available from NorPro, XZ16075, sieve fraction 180-425 μm, density 1.15 g / ml, pore volume 575 μl / g, specific surface area 55 m2 / g according to the BET measurement) was impregnated with a solution Pd (NO ₃ ) ₂ precursor until the initial moisture content was reached, dried at 110 ° С, calcined at 450 ° С in air, impregnated with KAuO ₂ solution (obtained by dissolving Au (OH) ₃ in KOH), dried at 110 ° С, reduced at 200 ° C (columns 1-2), 300 ° C (columns 3-4) or 400 ° C (columns 5-6) using the gas reservoir 5% H ₂ / N ₂ and Mob RGALI subsequent impregnation with a solution of KOAc. The library had a KOAc gradient from 15 to 40 g / L in the area from line 2 to line 7. The degree of Pd administration was 1.5 mg Pd per 0.4 ml of carrier. Two different degrees of administration of Au were chosen (Au / Pd = 0.5 in columns 1, 3, 5 and Au / Pd = 0.7 in columns 2, 4, 6). A silica-based comparative catalyst was loaded in line 1. The library was tested using a ramp test protocol with a fixed SV in the VA MCFB48 production reactor. The test results are summarized in table 6.

Table 6 Selectivity for CO ₂ Temperature at a degree of conversion of 45% STY Cl-containing precursors on SiO ₂ 7.11 154.2 738 Pd (NO ₃ ) ₂ on ZrO ₂ 5.51 145.4 797 * The demonstrated data were obtained on the basis of averaging for two atomic Au / Pd ratios (namely 0.5 and 0.7), at 40 g / L KOAc, calcining at 450 ° C and reducing at 400 ° C.

In addition, it is necessary to understand that the functions or structures of several components or stages can be combined to produce one component or one stage, or the functions or structures of one stage or one component can be divided between several stages or components. The present invention provides all of these combinations. Unless otherwise indicated, the dimensions and geometries of the various structures described herein are not intended to limit the invention, and other dimensions or geometries are possible. Several structural components or steps may be represented by a single integrated structure or step. Alternatively, one integrated structure or stage can be divided into several separate components or stages. In addition, although a feature of the present invention can be described in the context of only one of the illustrated embodiments, such a feature can be combined with one or more other features of other embodiments for any given application. In addition, based on the foregoing, it is necessary to understand that obtaining unique structures in the present invention and their use also constitute methods corresponding to the present invention.

The explanations and illustrations presented in this document are intended to familiarize other specialists in the relevant field with the invention, its principles and its practical application. Specialists in the relevant field can adapt and use the invention in many of its forms that can best suit the requirements of a particular use case. Accordingly, the specific proposed embodiments of the present invention are not intended to be exhaustive or limiting. Therefore, the scope of the invention must not be determined by reference to the above description, but instead it must be determined by reference to the attached claims, while including the full scope of equivalents to which such a claim will be entitled. Descriptions of all articles and references, including patent applications and publications, for all purposes are incorporated herein by reference.

Claims (32)

1. A method of producing a catalyst or procatalyst suitable for facilitating the production of alkenyl alkanoates, including:
the introduction of at least one solution of the catalyst precursor component containing palladium and gold, in contact with the carrier material, where at least one solution of the catalyst component precursor is an aqueous solution that contains one or more representatives selected from Pd (NH ₃ ) ₂ (NO ₂ ) ₂ , Pd (NH ₃ ) ₄ (OH) ₂ , Pd (NH ₃ ) ₄ (NO ₃ ) ₂ , Pd (NH ₃ ) ₄ (OAc) ₂ , Pd (NH ₃ ) ₂ ( OAc) ₂ , Pd (NH ₃ ) ₄ (HCO ₃ ) ₂ and from NaAuO ₂ , KAuO ₂ , NMe ₄ AuO ₂ , HAu (NO ₃ ) ₄ in nitric acid, or combinations thereof; and reduction of palladium or gold by contacting a reducing medium with a carrier material. 2. The method according to claim 1, where the solution of the precursor of the catalytic component containing palladium contains Pd (NH ₃ ) ₂ (NO ₂ ) ₂ , Pd (NH ₃ ) ₄ (OH) ₂ , Pd (NH ₃ ) ₄ (NO ₃ ) ₂ , Pd (NH ₃ ) ₄ (OAc) ₂ , Pd (NH ₃ ) ₂ (OAc) ₂ , Pd (NH ₃ ) ₄ (HCO ₃ ) ₂ , and the solution of the precursor of the catalytic component containing gold contains KAuO ₂ , NMe ₄ AuO ₂ , HAu (NO ₃ ) ₄ in nitric acid. 3. The method according to claim 1, where the solution of the precursor of the catalytic component containing palladium contains Pd (NH ₃ ) ₂ (NO ₂ ) ₂ , Pd (NH ₃ ) ₄ (OH) ₂ , Pd (NH ₃ ) ₄ (NO ₃ ) ₂ , Pd (NH ₃ ) ₄ (OAc) ₂ , Pd (NH ₃ ) ₂ (OAc) ₂ , Pd (NH ₃ ) ₄ (HCO ₃ ) ₂ , and the solution of the precursor of the catalytic component containing gold contains KAuO ₂ . 4. The method according to claim 1, where the solution of the precursor of the catalytic component containing gold contains NMe ₄ AuO ₂ , HAu (NO ₃ ) ₄ in nitric acid, and the solution of the precursor of the catalytic component containing palladium contains Pd (NO ₃ ) ₂ or palladium oxalate. 5. The method according to any one of claims 1 to 4, where the carrier material contains silica, alumina, alumina-silica, titanium dioxide, zirconia, niobium oxide, silicates, aluminosilicates, titanates, spinel, silicon carbide, silicon nitride , carbon, steatite, bentonite, clays, metals, glass, quartz, pumice, zeolites, non-zeolitic molecular sieves, or combinations thereof. 6. The method according to claim 5, where the carrier material contains zirconia. 7. The method according to claim 5, where the carrier material contains a layered carrier material. 8. The method according to claim 7, where the layered material of the carrier contains an inner layer and an outer layer, and the inner layer is essentially free of palladium and gold. 9. The method according to claim 1, where the stage of contacting includes contacting with the carrier material from about 1 to about 10 g of palladium and from about 0.5 to about 10 g of gold per liter of catalyst, while the amount of gold is in the range from about 10 to about 125 wt.% based on the weight of palladium. 10. The method according to claim 1, where the solution of the precursor of the catalytic component contains at least a third component containing rhodium. 11. The method according to claim 1, further comprising introducing potassium acetate into contact with the carrier material. 12. The method according to claim 11, where the potassium acetate is present in an amount in the range of from about 10 to 70 g per liter of catalyst. 13. A catalytic composition for producing alkenylalkanoates, containing:
support material containing at least palladium and gold contacted with it to form a catalyst or procatalyst, where the catalyst or procatalyst is obtained from one or more precursors, including one or more representatives selected from Pd (NH ₃ ) ₂ (NO ₂ ) ₂ , Pd (NH ₃ ) ₄ (OH) ₂ , Pd (NH ₃ ) ₄ (NO ₃ ) ₂ , Pd (NH ₃ ) ₄ (OAc) ₂ , Pd (NH ₃ ) ₂ (OAc) ₂ , Pd (NH ₃ ) ₄ (HCO ₃ ) ₂ and from NaAuO ₂ , KAuO ₂ , NMe ₄ AuO ₂ , HAu (NO ₃ ) ₄ in nitric acid, or combinations thereof. 14. The composition according to item 13, where the solution of the precursor of the catalytic component containing palladium contains Pd (NH ₃ ) ₂ (NO ₂ ) ₂ , Pd (NH ₃ ) ₄ (OH) ₂ , Pd (NH ₃ ) ₄ (NO ₃ ) ₂ , Pd (NH ₃ ) ₄ (OAc) ₂ , Pd (NH ₃ ) ₂ (OAc) ₂ , Pd (NH ₃ ) ₄ (HCO ₃ ) ₂ , and the solution of the precursor of the catalytic component containing gold contains KAuO ₂ , NMe ₄ AuO ₂ , HAu (NO ₃ ) ₄ in nitric acid. 15. The composition according to item 13, where the solution of the precursor of the catalytic component containing palladium contains Pd (NH ₃ ) ₂ (NO ₂ ) ₂ , Pd (NH ₃ ) ₄ (OH) ₂ , Pd (NH ₃ ) ₄ (NO ₃ ) ₂ , Pd (NH ₃ ) ₄ (OAc) ₂ , Pd (NH ₃ ) ₂ (OAc) ₂ , Pd (NH ₃ ) ₄ (HCO ₃ ) ₂ , and the solution of the catalyst component precursor containing gold contains KAuO ₂ . 16. The composition according to item 13, where the solution of the precursor of the catalytic component containing gold contains NMe ₄ AuO ₂ , HAu (NO ₃ ) ₄ in nitric acid, and the solution of the precursor of the catalytic component containing palladium contains Pd (NO ₃ ) ₂ or palladium oxalate. 17. The composition according to item 13, where the carrier material contains zirconium dioxide. 18. The composition of claim 13, wherein the carrier material comprises laminated carrier material. 19. The composition according to item 13, where the catalyst or procatalyst contains a third component containing rhodium. 20. The composition according to item 13, where the catalyst or procatalyst contains from about 1 to about 10 g of palladium and from about 0.5 to about 10 g of gold per liter of catalyst, while the amount of gold is in the range from about 10 to about 125 wt. .% based on the weight of palladium. 21. The composition according to item 13, where the catalyst or procatalyst contains potassium acetate. 22. The composition according to item 21, where the potassium acetate is present in an amount in the range of from about 10 to 70 g per liter of catalyst. 23. The composition of claim 13, wherein the carrier material comprises particles of a carrier material or ground carrier material. 24. A method of producing alkenylalkanoates, including:
the introduction of a feedstock containing alkene, alkanoic acid and an oxidizing agent into contact with a catalyst or procatalyst containing palladium and gold on a support material, where the catalyst or procatalyst is obtained from one or more precursors comprising one or more representatives selected from Pd (NH ₃ ) ₂ (NO ₂ ) ₂ , Pd (NH ₃ ) ₄ (OH) ₂ , Pd (NH ₃ ) ₄ (NO ₃ ) ₂ , Pd (NH ₃ ) ₄ (OAc) ₂ , Pd (NH ₃ ) ₂ ( OAc) ₂ , Pd (NH ₃ ) ₄ (HCO ₃ ) ₂ and from KAuO ₂ , NaAuO ₂ , NMe ₄ AuO ₂ , HAu (NO ₃ ) ₄ in nitric acid, or combinations thereof. 25. The method according to paragraph 24, where the precursor solution of the catalytic component containing palladium contains Pd (NH ₃ ) ₂ (NO ₂ ) ₂ , Pd (NH ₃ ) ₄ (OH) ₂ , Pd (NH ₃ ) ₄ (NO ₃ ) ₂ , Pd (NH ₃ ) ₄ (OAc) ₂ , Pd (NH ₃ ) ₂ (OAc) ₂ , Pd (NH ₃ ) ₄ (HCO ₃ ) ₂ , and the solution of the precursor of the catalytic component containing gold contains KAuO ₂ , NMe ₄ AuO ₂ , HAu (NO ₃ ) ₄ in nitric acid. 26. The method according to paragraph 24, where the solution of the precursor of the catalytic component containing palladium contains Pd (NH ₃ ) ₂ (NO ₂ ) ₂ , Pd (NH ₃ ) ₄ (OH) ₂ , Pd (NH ₃ ) ₄ (NO ₃ ) ₂ , Pd (NH ₃ ) ₄ (OAc) ₂ , Pd (NH ₃ ) ₂ (OAc) ₂ , Pd (NH ₃ ) ₄ (HCO ₃ ) ₂ , and the solution of the catalyst component precursor containing gold contains KAuO ₂ . 27. The method according to paragraph 24, where the solution of the precursor of the catalytic component containing gold contains NMe ₄ AuO ₂ , HAu (NO ₃ ) ₄ in nitric acid, and the solution of the precursor of the catalytic component containing palladium contains Pd (NO ₃ ) ₂ or palladium oxalate. 28. The method according to paragraph 24, where the alkene is ethylene, alkanoic acid is acetic acid, and the oxidizing agent is an oxygen-containing gas. 29. The method according to any one of paragraphs.24-28, where the catalyst or procatalyst comprises a third component containing rhodium. 30. The method according to paragraph 24, where the catalyst or procatalyst contains from about 1 to about 10 g of palladium, and from about 0.5 to about 10 g of palladium and from about 0.5 to about 10 g of gold per liter of catalyst, the amount of gold is from about 10 to about 125 wt.% based on the weight of palladium. 31. The method according to paragraph 24, where the carrier material contains zirconium dioxide. 32. The method according to paragraph 24, where the carrier material includes a layered carrier material.