MXPA00007346A - Direct oxidation of cycloalkanes - Google Patents

Abstract

A catalytic process is disclosed for oxidizing cycloalkanes directly to form, in a single step, a mixture containing the corresponding alcohol and ketone. In particular, the invention relates to oxidizing a cycloalkane by contacting it with a source of oxygen and a catalytic amount of a heterogeneous catalyst. The catalysts of the invention include gold (including gold sol-gel compounds) and sol-gel compounds containing particularcombinations of Cr, Co, Zr, Ta, Si, Mg, Nb, Al and Ti, wherein certain of those metals have been combined with an oxide, such as an inorganic matrix of hydroxides or oxides, or combinations thereof. The catalysts may also optionally be supported on a suitable support member.

Description

DIRECT OXIDATION OF CICLOALCANOS Field of Invention The invention generally relates to an improved catalytic process for the oxidation of cycloalkanes to form a mixture containing the corresponding alcohol and ketone. In particular, the invention relates directly to the oxidation of cyclohexane to form a mixture containing cyclohexane and cyclohexane on contact with cyclohexane with an oxygen source and a catalytic amount of a heterogeneous gold or sol-gel compound. containing particular combinations of Cr, Co, Zr, Ta, Si, Ti, Nb, Al and Mg, where certain of those metals are combined with an oxide.

Background of the Invention Industrial processes for the production of cyclohexanol and cyclohexanone from cyclohexane are currently of considerable commercial significance and are described in the patent literature. In industrial practice Ref: 121532 Typically, the cyclohexane is oxidized to form a reaction mixture containing cyclohexyl hydroxyperoxide. { CHHP). The resulting CHHP is decomposed, optionally in the presence of a catalyst, to form a reaction mixture containing cyclohexanol and cyclohexanone. In industry, such a mixture is known as a C / A mixture (ketone / alcohol), and can easily be oxidized to produce adipic acid, which is an important reagent in the processes for the preparation of certain condensation polymers, notably polyamides. Due to the large volumes of adipic acid consumed in these and other processes, improvement in the processes for the production of adipic acid and its precursors can be used to improve the benefits of beneficial costs.

A representative example of the oxidation of cyclohexane to CHHP can be found in Druliner et al., US Patent No. 4,326.08., In which cobalt salts are used as homogeneous catalysts to form a reaction mixture containing CHHP, and for a subsequently decompose the resulting CHHP to form a mixture containing C and A.

Drulmer et al., In W098 / 34894, August 4, 1998, discloses the decomposition of a hydroperoxide by contacting it with a catalytic amount of a heterogeneous catalyst selected from the group consisting of Au (gold), Ag (silver) , and Cu (copper). Preferably, the catalyst is supported on a solid support such as S? 02, A1203, carbon, MgO or T? 02.

Komiya et al., (J Molecular Catalysis A, 117, pages 21-37, 1997) studies the oxidation of alkanes to the corresponding alcohols and ketones using molecular catalysts of oxygen and copper. However, the presence of stoichiometric amounts of aldehydes is required in order to form an intermediate peracid that functions as the current oxidized reagent.

Pugí, K. (United States Patent No. 3,530,185) teaches a process for the oxidation of cyclohexane to C and A, optionally using a soluble cobalt catalyst. However, the The resulting mixture contains significant amounts of CHHP.

Haruta et al., (EP 0,709,360) describes a process for oxidizing a saturated hydrocarbon to the corresponding alcohol in the presence of a reducing agent such as hydrogen. Hayasi et al (WO 97/34692) discloses a partially oxidized catalyst comprising gold, titanium oxide and a useful carrier for the partial oxidation of hydrocarbons.

In view of the foregoing, it is desired to have catalysts that produce C and A directly from the cyclohexane without the step of further decomposition of CHHP resulting in simple processing and less product loss. The use of most of the desirable catalysts results in high conversion and selectivity together with little or no CHHP or high oxidation products present in the final product.

In this way it is an object of the present invention to overcome some of the deficiencies of the prior art and also to provide a process for the oxidation in a step of cycloalkanes (cyclohexane) to the corresponding alcohol (cyclohexanol) and ketone (cyclohexanone) using a heterogeneous catalyst that results in having little or no CHHP present in the final product mixture. Other objects and advantages of the present invention will be apparent to those skilled in the art with reference to the detailed description that follows.

Brief description of the invention.

In accordance with the present invention, there is provided an improved process for oxidizing a cycloalkane (preferably cyclohexane) to form a reaction mixture containing a corresponding alcohol (A) and a ketone (C), the improvement comprising oxidizing a cycloalkane by contacting the cycloalkane with an oxygen source and a catalytic amount of a heterogeneous catalyst selected from the group consisting of (1) gold and (2) a sol-gel compound comprising (a) one or more members selected from a first group consisting of Cr, Co and Ti and (b) one or more members selected from a second group that consists of Zr, Nb, Ta, Si, Al, Mg and Ti, where the selected members of (b) are combined with an oxide and where the members1 of the first group can not be the same as the members of the second group. Preferably, an inorganic matrix of hydroxides or oxides, or combinations thereof, is used as the oxide.

The catalysts are optionally supported on a solid catalyst support member. An initiator, preferably propionaldehyde, is also optionally present with the catalyst. Particularly preferred catalysts include gold supported on AI2O3 and sol-gel compounds containing Au, Cr and / or Co.

Detailed Description of the Preferred Modalities.

In accordance with the present invention, the cycloalkanes can be oxidized directly in the presence of an oxygen source and a catalyst to yield the corresponding alcohol and ketone with little or no corresponding hydroperoxide present in the final product.

The heterogeneous catalysts of the invention include Au (including, but not limited to, gold sol-gel compounds), preferably applied to an appropriate solid support, and sol-gel compounds comprising (a) one or more of Cr, Co and Ti and (b) one or more of Zr, Ta, Nb, Si, Al, Mg and Ti that combine with an oxide, but where these are at least two different metals present in the compound For the supported Au catalyst, the metal for the support percentage it can vary from about 0.01 to about 50 weight percent, and is preferably about 0.1 to about 10 weight percent. Suitable supports include S? 02 (silica), AI2O3 (alumina), Zr02 (zircsnia), C (carbon) and T1O2 (titania). Alumina is the preferred support, and Au supported in alumina is a particularly preferred catalyst of the invention Some of the heterogeneous catalysts of the invention can be readily obtained prepared from manufactures, or they can be prepared from appropriate starting materials using methods known in the art. These methods may include sol-gel techniques as described in more detail below to prepare both gold compounds and other non-sol-gel gold compounds. The gold supported catalysts can be prepared by any known standard procedure to give good gold dispersion, such as evaporation techniques or colloidal dispersion coatings.

In particular, gold particles of ultra-fine size are preferred. Such small gold particles (often smaller than 10 nm) can be prepared according to Haruta, M. , "Size- and Support-Depndency in the Catalysis of Gold", Catalysis Today 36 (1997) 153-166 and Tsubota et al., Preparation of Catalysts V, pages 695-704 (1991). Such gold preparations produce samples that are purple-pink in color instead of the typical bronze color associated with gold and result in highly dispersing gold catalysts when placed on an appropriate support member. These highly dispersing gold particles are typically from about 3 nm to about 15 nm in diameter.

The solid catalyst support member, including S? 02, Al203, Zr02, carbon, or T? 02, can be amorphous or crystalline, or a mixture of amorphous and crystalline forms. The selection of an optimum average particle size for the catalyst supports will depend on such process parameters as residence time in the reactor and desired reactor flow rates. Usually, the average particle size of the selected support can vary from about 0.005 mm to about 5 mm. Catalysts having a surface area greater than 10m2 / g are preferred since they increase the surface area of the catalyst having a direct correlation with increased reaction ratios in the group of experiments. Brackets that have much larger surface areas can also be employed, but the inherent fragility of the large surface area catalysts, and the subsequent problems in maintaining an acceptable particle size distribution, must establish an upper limit of practical on the surface area of the catalyst support.

Other catalysts useful in the present invention comprise certain metals (including metal ions) combined with an oxide, such as an inorganic matrix of hydroxides or oxides, or combinations thereof. The metals include Cr, Co, Zr, Ta, Nb, Al, Si, Ti and Mg, present in combinations as they have been placed. The mole percentage of the metals in the matrix can vary, as is the number of different metals and their relative relationships. These may also have a variable hydroxide content, which may depend on the calcination temperature, if carried out, and other parameters. The transition metals Co and Cr may be present as inorganic salts while Zr, Ta, Nb, Si, Al, Ti and Mg may be present as an oxide, a hydroxide or combinations thereof. (It should be noted that for the purpose, the corresponding anions are not shown for these cations in the formulas identified here). The typical preparations involve sol-gel chemistry where the metals are co-hydrolyzed and / or enclosed within an inorganic matrix. A better dispersion and uniformity of the metal can be obtained compared to what is normally achieved using most conventional synthetic methods. The inorganic matrix can optionally be supported on an appropriate support member, such as S? 02, AI2O3, Zr02, carbon, or T? 02. Preferred catalysts of this type are those containing Cr and / or Co.

A "sol-gel technique" is a process in which the free flowing fluid solution, "sol", is prepared by first dissolving appropriate precursor materials such as colloids, alkoxides or metal salts in a solvent. The "sol" is then dosed with a reagent to initiate the reactive polymerization of the precursor. A typical example is tertethoxyorthosilicate (TEOS) dissolved in ethanol. Water is added, with a trace of acid or base as catalyst to initiate hydrolysis. As polymerization and cross-linking processes, the free flux of "sol" is increased in viscosity and may eventually be placed to a rigid "gel". The "gel" consists of a cross-linked channel of the desired material that encapsulates the original solvent within its open porous structure. The "gel" can then be dried, typically either by simple heating in a dry air flow to produce a xerogel or by trapping the solvent to remove it by placing it with a supercritical fluid such as liquid CO2 to produce an airgel. These aerogels and xerogels can optionally be calcined at elevated temperatures (> 200 ° C) resulting in products that typically have several porous structures and consequently high surface areas.

In the practice of the invention, the catalysts can be contacted with a cycloalkane, such as cyclohexane, by the formulation in a catalyst bed, which is placed to provide intimate contact between the catalyst and the reagents. Alternatively, the catalysts can be mixed with reaction mixtures using techniques known in the art. The process of the invention is suitable for group or cycloalkane oxidation processes These processes can be performed under a wide variety of conditions.

Appropriate reaction temperatures for the process of the invention are in the range from about 160 ° C to about 200 ° C. temperatures descending around 160 ° C to around 180 ° C are typically preferred. Reaction pressures may preferably be in the pressure range from about 69 kPa to about 2760 kPa (10-400 psi), and pressures from about 276 kPa to about 1380 kPa (40-200 psi) are the More preferred The reaction time varies in inverse relationship to the reaction temperature, and is typically in the range from about 2 to about 30 minutes.

The reaction process may optionally contain an initiator, preferably an aliphatic aldehyde of 2-6 carbons. The most preferred is the propionalde gone.

The oxygen source used in the oxidation can be a molecular oxygen itself but Conveniently it is air or other mixtures of nitrogen and oxygen with a greater or lesser proportion of oxygen than air, obtained, for example, by the mixture of oxygen or nitrogen with air. However, air is preferred.

The following non-limiting Examples are provided to further illustrate and enable the invention, but are not intended to limit it in any way.

Materials and methods Experiment 1 -1% Au in g-alumina In accordance with the general gold removal technique of Tsubota et al., Preparation of Catalyst V, pages 695-704 (1991) to produce ultra fine gold particles, 10 g of powdered alumina - 60 g of sieves are mixed ( Alfa Aesar, Ward Hill, MA) in a solution of 0.2 g of gold trichloride in 50 mL of water containing 1 L of concentrated HCl. The pH of the mixture was adjusted to 9.6 with a sodium carbonate solution and then 0.69 g of calcium citrate was added. After stirring for 2 hours at room temperature, the solid was recovered by filtration and washed thoroughly with distilled water. The recovered solid was calcined in an air flow (100 mL / minute) at 250 ° C for 5 hours, cooled and then stored in tightly capped small bottles to be tested as a cyclohexane oxidation catalyst. The resulting catalyst was purple / pink in color and had a particle size of 8 nm as determined by X-ray diffraction (XRD).

Experiment 2 CrZrO Cr0 05 (ZrQ2-_ (OH) __) 0 95 218 mL of ethanol (Quantum Chemical, Newark, NJ, particularly dehydrated) were combined with 93.4 g of zirconium n-propoxide (70% by weight in n-propanol, Alpha 22989, Ward Hill, MA) in a dry box of N2. in an inert atmosphere. 5.24 g of chromium (III) acetylacetonate (Aldrich, 20, 223-2, Ward Hill MA) was dissolved in 218 mL of ethanol and added to this solution. In a separate container, I mix 218 mL of ethanol with 20.5 L of water and 2.45 mL of glacial acetic acid (JT Baker, 6903-05, Phi 1 lipsburg, NJ) and 1.91 mL of 70% by weight nitric acid (EM Sciences, Gibbstown, NJ) .

The aqueous solution was added, in a dropwise fashion, to the zirconium alkoxide solution. The experiment was carried out in a resin kettle under a nitrogen flow layer during the addition of the aqueous solution. During hydrolysis and before the observation of a gel point, some opaque formation and possible white particles were noted in the zirconium alkoxide solution. The opaque gel material was allowed to age at an ambient temperature for at least 24 hours The material was dried at 120 ° C in 1 atmosphere before being used. For some experiments, the material was pressed at 20,000 psi in small discs and granulated to a screen sieve of -10, +20 mesh.

Experiment 2a CrZrO (extracted) Cr0 05 (ZrQ2-x (OH) 2 x) or 95 The compounds were made as in Experiment 2 but instead of air drying, these were extracted using supercritical CO 2. The solvent removal was performed to place the material in the agitated autoclave. The C02 gas was purged on the catalyst for a period of 7 hours, at 40 ° C and a pressure of 3500 psi. The xerogel produced after this exposure was a free-flowing powder.

E ncrease 3 CrTaO Cr, 0. (TaO2._ »(OH)? B 95 350 mL of ethanol (Quantum Chemical, Newark, NJ, particularly dehydrated) were combined with 115.8 g of tantalum ethoxide (Ta (Oet) 5, Aldrich, 33, 91103, Milwaukee, Wl) in a dry cation of N 2 in an inert atmosphere. 5.24 g of chromium (III) acetyl acetate (Aldrich, 20, 223-2, Ward Hill MA) was dissolved in 350 mL of ethanol and added to the alkoxide solution. In a separate vessel, 350 L of ethanol was mixed with 25.7 mL of water and 3.06 mL of glacial acetic acid (J.T. Baker, 6903-05, Phillipsburg, NJ) and 2.39 mL of 70% by weight nitric acid (EM Sciences, Gibbstown, NJ).

The aqueous solution was added, in a dropwise manner, to the tantalum alkoxide solution containing soluble chromium acetylacetone. The material was stored in a resin kettle and a layer of nitrogen or nitrogen was placed during this addition. After the hydrolysis a dark, clear purple gel was formed. A clear gel spot was observed after about seven days at room temperature under nitrogen flow.

The material is dried at 120 ° C in 1 atmosphere before use. For some experiments, the material was pressed at 20,000 psi in small discs and granulated to a screen sieve of -10 mesh, +20 Experiment 3a CrTaO (extracted) Cr0 05 (Ta02-5-? (OH)?) Or .5 The compounds were worked up as in Experiment 3, but were further extracted by the same procedure described in Experiment 2a.

Experiment 4 CrTiO Cr. 2 (T? Q2-x (OH) 2) or 8 13. 85 mL of a 60% volume solution in ethanol containing titanium n-butoxide [Aldrich, 24-411-2] in ethanol was added to 50.08 mL of ethanol under an inert atmosphere of nitrogen. Slowly add 6.06 mL of a 1.5 molar aqueous solution (metal content) separated from 1.5 molar chromium hydroxide acetate [Aldrich, 31.810-8] to the alcohol solution, with slow stirring, to form a green colloidal gel . The material is dried at 120 ° C in air before use.

Experiment 5 CoCrTiO Cop 2Cr0 2 (T? O_-. (OH) 2x) 14.57 mL of a 60% volume solution in ethanol containing titanium n-butoxide [Aldrich, 24-411-2] was added to 52.68 mL of ethanol. 8.50 mL of a 1.5 molar aqueous solution of chromium hydroxide acetate [Aldrich, 31-810-8] and 12.75 mL of a 1.0 M aqueous solution of cobalt chloride [Alpha, 12303], were added to the solution of alkoxide During the addition, the glass vessel was gently stirred under a nitrogen atmosphere. The gelled material is dried at 120 ° C in air before use.

Experiment 6 T1S1O Uncle 1 Sip 9 (02-v (OH);.) 1 915 mL of a solution of tetraethylorthosilicate (Aldrich, 13, 190-3) containing 60% volume of alkoxide in ethanol was added to 26.43 mL of a solution of titanium n-butoxide (Aldrich, 24, 411-2), also containing 60% volume of the alkoxide in ethanol. 67.43 mL of ethanol was added to form a mixed alkoxide solution. The solution is taken care of in a nitrogen atmosphere.

A solution containing 3,712 mL of water was mixed with 0.515 mL of glacial acetic acid (EM Sciences, X0409PS-1) was added to the alkoxide solution. During the addition of the aqueous components, the glass vessel was gently stirred under a nitrogen atmosphere. A gelatinous white gel was formed almost immediately upon addition and allowed to age at room temperature for at least 24 hours. The gelled material is dried at 120 ° C in air before use.

Experiment 7 CoSiTiO COp 5TIQ jS p i (02-x (OH) 2x) 5 3. 86 mL of TEOS at 60% volume, 23,661 mL of titanium n-butoxide at 60% volume, and 16.45 mL of ethanol were used to form the alkoxide solution. To this solution, 3.74 mL of H20, 0.425 mL of glacial acetic acid, and 51,879 mL of a 1.0M solution of cobalt (II) chloride (alpha, 12303) in ethanol were added, while gently stirring the glass container. A layer of nitrogen was used through this. A reddish blue gelatinous material was produced. After aging for 24 hours in the air, the material is dried at 120 ° C before the cyano oxidation evaluations.

Experiment 8 AuMgCrTiO Au0 oo 5Mq. oo ° 9Cr. 0o495 (T? Q2-x (OH) 2x) or 98 46.14 mL of ethanol (Quantum Chemical, 290, Newark, NJ, particularly dehydrated) was combined with 20,214 mL of a 60% volume solution in ethanol, containing titanium butoxide (Aldrich, 24, 411-2), under a atmosphere of inert nitrogen. 0.818 ml of an aqueous solution 0 219 M containing AUCI3 (Aldrich, 33, 404-9) prepared using water and a molar ratio of HCl-Au of 3-1 of 37% by weight of HCL E was added. M. Sciences, Gibbstown, NJ) simultaneously with 2.00 ml of 0.179 M aqueous magnesium citrate (Alpha, 39368), 0.119 ml of 1 5M aqueous chromium hydroxide acetate, Cr3 (OH) 2 (CH3COO) 7 (Aldrich, 31, 810 -8), and 0.709 ml of glacial acetic acid, (JT Baker, 6903-05, Phi llipsburg, NJ).

Aqueous solutions were added simultaneously to the alkoxide solution. The vessel was gently stirred during the addition. A nebulous green / white gelatinous material was produced. After aging for at least 24 hours in air, the material is dried at 120 ° C in a vacuum oven, and subsequently heated up to 250 ° C in the air for five hours, before the oxidation evaluations of Experiment 9 AuMgCrTiO Au0 0227 Mg0 0909 Cr »_227 (T? Q2-x (OH) 2x) _ 8636 The same procedure and reagents were used as described for Experiment 8, with the following differences: 3. 216 ml of a solution of AUCI3 15,243 ml of a solution of titanium n-butoxide 15,749 ml of a solution of magnesium citrate 0. 469 ml of a solution of chromium hydroxide acetate 34.789 ml of ethanol 0.535 ml of glacial acetic acid A nebulous green / white gel was produced, and treated in the same manner as described for Experiment 8.

Experiment 10 AuMgCrZrO Auo 0095 Mg0 o_76 Cr0 0952 (Z r02- ^ (OH) 2x) or 8.8 1. 836 ml of ethanol (Quantum Chemical, 290, Newark, NJ, particularly dehydrated) was combined with 65,530 ml of a 0.558 M solution in ethanol containing zirconium n-propoxide (Alfa, 22989) under an inert nitrogen atmosphere, adding 1827 mi of a 0.2248M aqueous solution containing AuCl3 (Aldrich, 33, 404-9) simultaneously with 11,408 ml of 0.180M aqueous magnesium citrate (Alfa, 39368), and 2738 ml of 1.5M aqueous chromium hydroxide acetate, Cr3 ( OH) 2 (CH3COO) 7 (Aldrich, 31, 810-8). Aqueous solutions were added simultaneously to the alkoxide solution. The container stirred Gently during this addition. A cloudy yellow / white gelatinous material was produced. After aging for at least 24 hours in air, the material is dried at 120 ° C in a vacuum oven, and subsequently heated up to 250 ° C in air for five hours, before cyano oxidation evaluations.

Experiment 11 AuMgCrAlO Au0 0095 Mq0 0476 Cr0 0952 (AlOi 5-x (OH) 2?) Or 8476 69. 574 ml of a 0.05M solution, in ethanol, of aluminum isopropoxide (Aldrich, 22, 904-7) was added to the container. In a second step, 0.525 ml of a 0.0744M aqueous solution containing AuCl3 (Aldrich, 33, 404-9) was added simultaneously with 1086 ml of 0 180M aqueous magnesium citrate (Alpha, 393668), 0.361 ml 1.5M aqueous chrome, Cr3 (OH) 2 (CH3COO) 7 (Aldrich, 31, 810-8). Aqueous solutions were added simultaneously to the alkoxide solution. The vessel was stirred gently during this addition. A red, hazy gel was produced. After aging for at least 24 hours in air, the material is dried at 120 ° C in a vacuum oven, and subsequently heated up to 250 ° C in air for five hours, before cyano oxidation evaluations. This Experiment produced a combination of aluminum base of hydroxides and oxides.

Experiment 12 AuMgCrAlO Au0 0952 Mg. oJ76 Cr0? 90 (A10_ 5 - »(OH);.) fl 7524 The same procedure was used as in Experiment 11, except for the changes in volumes as listed below. A red, hazy gel was produced. 0. 592 ml of an AuCl3 solution 69.552 ml of the aluminum isopropoxide solution 1.223 ml of the magnesium citrate solution 0.587 ml of the solution of chromium hydroxide acetate.

Examples.

The reactions were developed using small glass bottles of 2 mL or 30 mL. The starting solution for all reactions was distilled cyclohexane, or spectral grade cyclohexane, containing a known wt% (approximately 1-2%) of CB (chlorobenzene) as a reference for internal GC (gas chromatography). All reaction products were first derivatized with BSTFA (bis (trimethylsilyl) tpf luoroacetamide / 1% trifluoride, Supelco, Inc., Bellefornte, Pennsyl vania), a standard derivatizing agent before analysis by CG. The procedure for the BSTFA derivative consists of adding 10% by volume of BSTFA per volume of product to an aliquot of reaction product, stirring for 1 hour at 50 ° C and cooling to room temperature. CG analysis was performed using a 15 m DB-17 capillary column with an internal diameter of 0.32 mm (J. _ Y¡. Scientific, Folsum, CA). the liquid phase of the column is comprised of 50% by weight of polysioxane of (phenyl) methyl.

All reactions were heated by the times shown in Tables 1-IV under Warm-up Time until the set temperature was reached. The reactions were maintained at this temperature for the times shown under Wait Time, and then the contents were cooled and analyzed.

The results of the GC analyzes of the reaction product are shown in Tables I, II, III and IV as% Conversion (% of cyclohexane converted to analysable products by CG),% Selectivity (% of the ratio of the sum of products C, A and CHHP divided by the sum total of products), and as CHHP / (C, A, CHHP) (CHHP / (C + A + CHHP) product ratio.) All calculations are based on product moplings as determined by the CG.The molarity (M) of a given product compound is calculated from the equation: % of area.composed X M.B X R. F. composed% of areac_ The R.F. of the compound (CG response factor for a given compound) was determined from the Calibration solutions containing known quantities of each product compound measured by GC and chlorobenzene from the equation: M. ompues t o / o e 3 r e a .ompues t o K. r. Compu e M.B /. of area.

The% Conversion and% Selectivity are defined additionally by the equations: 100 x Sum of M for all product ccppuestos Conversion% = Me, cloh.xano (= 9.29 M) 100 x Sum of M for (C + A + CHHP). of Selectivity = Sum of M for all product compounds Examples 1-22 and Comparative Examples A-L (Tables I and II) give the results of the cyclohexane oxidation experiments obtained using small 2 mL glass bottles. Each small vial was charged with 0.5 or 1.0 mL of a cyclohexane / CB solution and pressurized to 500 psig with air. The small bottles were then heated to the temperatures shown and for the indicated times. The small bottles are they agitated with stirring bars covered with Teflon®.

Examples 23-28 and Comparative Examples M-S (Tables III and IV) give the results of the cyclohexane oxidation experiments obtained using small 30 mL glass jars. Each small vial was charged with 5.0 mL of cyclohexane / CB solution and pressurized to 500 psig with air. The small bottles were then heated to the temperatures shown and for the indicated times, and stirred. Some examples involve the use of an initiator (propionaldehyde).

TABLE I Time Tenf. of Time Heating Method of CHHP / C Catalyst, of Sol. Reaction expected%%.?. CHH E_. g. prep. my? n ° C Min. Min. Copv. Select P 1 AU / A1203, Exp.l 0.5 160 36 1.85 97.4 0.03 0.0202 2 AU / A1203, Exp.l 1.0 160 14. 2.82 96.6 0.0201 3 AU / A1203, Exp.l 1.0 170 1.79 96.4 0.01 u, xp _ 0 0204 Au / A1203, Exp 1 1 0 170 39 7 1 90 95 7 OO 0203 AU / A1203, Exp 1 0 5 170 39 7 4 28 93 9 O 01 O 0206 AU / A1203, Exp 1 0 5 170 39 7 4 31 93 8 O 01 O 0200 Au / A1203, Exp 1 1 O 190 45 2 2 06 91 6 OO 0113 Au / A1203, Exp 1 1 0 190 45 10 2 30 90 8 OO 0106 CrZrO, Exp 2 O 5 160 36 9 O 68 - O 09 O 0202 CrZrO, Exp 2"O 5 170 39 7 4 77 86 2 0 0 O 0201 CrTaO, Exp 3 0 5 160 36 9 1 97 98 1 O 11 O 0202 CrTaO, Exp 3"0 5 170 39 7 3 91 87 2 O 01 O 0210 CrTiO, Exp 4 0 5 160 36 9 3 53 96 8 O 03 O 0196 CrTiO, Exp 4 O. 170 39 7 3 85 89 6 OO 0215 CoSiTiO, Exp 7 O 5 160 36 9 3 75 97 8 OO 0206 CoCrTiO, Exp 5 O 5 160 36 9 3 92 94 7 OO 0209 CoCrTiO, Exp 5 O 5 170 39 7 3 73 93 1 OO 0202 T? S_0, Exp 6 0 5 160 36 9 0 -0 0209 9 AuMgCrTiO, Exp.9 0.5 170 39 6 4.10 91.6 0.19 0.0106 0 AuMgCrZrO, Exp.10 0.5 170 6 4.91 92.3 0 0.0208 1 AuMgCrAIO, Exp.11 0.5 170 39 6 2.94 98.9 0 0.0202 2 AuMgCrAIO, Exp.12 0.5 170 39 6 3.22 98.6 0 0.0205 TABLE II Temp. Reaction time of the solar heats. Waiting time% CHHP / C.A E.}. . Catalyst, g. my "C Min. Min.% Conv. Select .CHHP Without 0.5 160 36 9 7.81 85.6 0.21 Catalyst Without 0.5 160 36 9 7.67 87.5 0.11 Catali zador Sin 0.5 160 36 9 4.24 97.2 0.51 Catalyst Without 1.0 160 36 9 4.60 96.4 0.51 Catali zado r Sin 1.0 160 36 144 4.21 85.8 0.02 Catal i zador Sin 1.0 170 39 7 2.98 85.6 0.01 Cat al i z ador Sin 1.0 170 39 7 3.19 85.5 0.05 Catalyst Without 0.5 170 39 7 5.27 83.2 0.01 Catali z ador I S? N 0.5 170 39 7 5.81 83.1 0.02 CatalÃ? Ador J S? N 0.5 170 39 7 6.23 78.3 0.02 K S? N 1.0 190 45 2 2.50 84.9 0 Catali z ador L Sln 1.0 190 45 10 2.40 84.8 0 Catali zador TABLE III ~ 23 AU / A120 Exp.l 5 ~ 0 170 15 30 7.00 79.6 C > 575 3, 0.0501 24 AU / A120 Exp.l 5.0 170 15 30 6.82 83.8 0 0.5 3, 0.0527 25 A- / A120 Exp.l 5.0 170 15 30 2.72 97.2 0 0.3 3, 0.0518 26 Au / A120 Exp.l 5.0 170 15 30 3.48 96.3 0 0.1 3, 0.0550 27 AU / A120 Exp.l 5.0 170. 45 30 4.63 96.0 0.1 0 3, 9 0.0511 AuMgCrT Exp. 10, 0.0507 TABLE IV E. Catalyzed Sun Temp Time Time%. CHHP /% or, g de de de Conv. Select C.A. Propion my reaction is waiting. CHHP aldehyde on ° C amient Mm. or Hin. M Sin 5.0 170 15 30 4.38 85.4 0.08 0.1 Catalyzed S n 69.4 0.05 Catalyzed Without 69.3 0 03 Catalyzed Without 83.8 0.10 Catalizad Without 81.5 0.04 Catalyzed Without Catalizad Without 5 O Catalizad Although the particular embodiments of the present invention have been described in the foregoing description, it will be understood by those skilled in the art that the invention is capable of numerous modifications, substitutions and arrangements without departing from the spirit or essential attributes of the invention. reference to the appended claims, rather than to the previous specification, as the indicator of the scope of the invention It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Having described the invention as above, property is claimed as contained in the following

Claims (18)

Claims

1. A process for the oxidation of a cycloalkane in a reaction mixture to form a product mixture containing a corresponding alcohol and ketone, the improvement characterized in that it comprises: contacting the reaction with an oxygen source and a catalytic amount of a heterogeneous catalyst in which the catalyst is (1) gold, (2) a sol-gel gold compound, or (3) a sol-gel compound comprising (a) one or more members selected from a first group consisting of Cr, Co and Ti and (b) one or more members selected from a second group consisting of Zr, Ta, Nb, Si, Mg, Al and Ti with the proviso that the hydrogen is not present in the reaction mixture if the catalyst is gold supported on titania or a gold sol-gel compound supported on titania and the selected members of (b) are combined with an oxide and wherein the members of group (a) can not be the same as the members of group (b).

2. The process according to claim 1, characterized in that the cycloalkane is cyclohexane.

3. The process according to claim 2, characterized in that the corresponding alcohol is cyclohexanol and the corresponding ketone is cyclohexanone.

4. The process according to claim 1, characterized in that the heterogeneous catalyst is supported on a catalyst support member.

5. The process according to claim 4, characterized in that the catalyst support member is AI2O3.

6. The process according to claim 4 or 5, characterized in that the catalyst is gold and wherein the gold is present in the support member as well dispersed particles having a diameter from 3 nm to 15 nm.

7. The process according to claim 1, characterized in that the reaction temperature is from 160 ° C to 200 ° C, and the reaction pressure is from 69 kPa to 2760 kPa.

8. The process according to claim 7, characterized in that the reaction temperature is from 160 ° C to 180 ° C.

9. The process according to claim 1, characterized in that the source of oxygen is air

10. The process according to claim 6, characterized in that the gold is from 0.1 to 10 weight percent of the catalyst and support member.

11. The process according to claim 1, characterized in that an initiator is also present with the catalyst.

12. The process according to claim 11, characterized in that the initiator is propionaldehyde.

13. The process according to claim 1, characterized in that the sol-gel compound contains Cr and / or Co.

14. The process according to claim 1, characterized in that the oxide is an inorganic matrix of hydroxides or oxides, or combinations thereof.

15. The process according to claim 14, characterized in that the inorganic matrix is an aluminum-based combination of hydroxides and oxides.

16. The process according to claim 1, characterized in that the gold catalyst is in the form of a sol-gel compound.

17. The process according to claim 1, characterized in that the gold The catalyst is in the form of a sol-gel compound comprising Au and Cr.

18. The process of any of the foregoing claims, characterized in that the hydrogen is not present in the reaction mixture.