CN101346181A - Metal nitrate conversion method - Google Patents

Abstract

A method is described for converting a supported metal nitrate into the corresponding supported metal oxide comprising heating the metal nitrate to effect its decomposition under a gas mixture that contains nitric oxide and has an oxygen content of <5% by volume. The method provides very highly dispersed metal oxide on the support material. The metal oxide is useful as a catalyst or as a catalyst precursor.

Description

Metal nitrate conversion method

The present invention relates to metal nitrate is changed into the method for respective metal oxide.

Metal nitrate is because its relatively low cost and making easily, and becomes useful metal oxide precursor.They change into corresponding metal oxide usually in the manufacturing of catalyst or adsorbent.In the manufacturing of catalyst or adsorbent, typically one or more soluble metal nitrate are impregnated on the suitable carriers material, and are dried except that desolvating.Then in being commonly referred to as the step of calcining, the carrier of dipping being heated in air under metal nitrate decomposition temperature or the above high temperature, thereby forming metal oxide.Yet this method does not always produce gratifying oxidation material.Especially, wherein metal oxide is reducible metal oxide, and the crystallite of metal oxide and the reducing metal that obtains by these methods thus disperses and distributes relatively poor usually.

People have attempted these preparation methods are changed.EP0421502 has described a kind of method for preparing catalyst or catalyst precarsor, and the cobalt nitrate that wherein will load on the porous inert carrier is calcined at least in the atmosphere that contains 20% volume nitrogen oxide (not considering the water content of atmosphere).Nitrogen oxide preferably derives from cobalt nitrate purge or with the decomposition under the low speed purge calcining furnace condition not therein.This calcining shows the cobalt oxide crystallite agglomerate of producing 1-10 μ m size.

In above-mentioned EP0421502, the calcining of cobalt nitrate is to carry out in air, and nitrogen oxide is provided by metal nitrate itself.Yet and undeclared concrete nitrogen oxide, this calcining during, main nitrogen oxide will be nitrogen dioxide (NO ₂).

The metal oxide of load is as catalyst, catalyst precarsor and adsorbent, and its validity is relevant with the dispersion of metal oxide on carrier.Therefore wish to improve the dispersion of the metal oxide that obtains by metal nitrate.

We have found to produce the metal oxide of high dispersion and equally distributed load comprising nitric oxide especially and not containing or contain the heat treatment of hanging down under the admixture of gas of measuring oxygen.Compare with the method for EP0421502, do not need the nitrogen oxide of high concentration and this method can provide very little metal oxide agglomerate, its crystallite dimension＜10 nanometers in the method for the present invention.

Therefore the invention provides the method that a kind of metal nitrate with load changes into the metal oxide of respective load, described method be included in comprise nitric oxide and have＜admixture of gas of 5 volume % oxygen content under heating of metal nitrate, thereby realize the decomposition of metal nitrate.

The present invention also provides a kind of metal oxide of the load that can be obtained by said method.

Therefore method of the present invention comprise make comprise nitric oxide and have＜admixture of gas of 5 volume % oxygen content is through the metal nitrate of overload, and the metal nitrate that will be exposed to this admixture of gas is heated to its decomposition temperature at least.Therefore, nitric oxide is not to be produced by the decomposition of metal nitrate in the present invention, but should be present in the flowing gas mixture that metal nitrate exposes during decomposing.

Metal nitrate is load in many ways, comprises doing mixing, molten nitrate mixing, precipitation and dipping.Preferred dipping.For example can metal nitrate be impregnated on the carrier material from the aqueous solution or non-aqueous solution such as ethanol, described solution can comprise other material, is dried then to remove to desolvate.Can there be one or more metal nitrates in the solution.Can carry out the one or many impregnation steps, thereby improve content of metal or the pantostrat of different metal nitrate was provided before drying.Can use the known any method of catalyst or adsorbent manufacturing those skilled in the art to flood, but preferably by so-called " dry type " dipping or " just wet " dipping, because the use amount of solvent and the amount to be removed in drying are minimized.Just wet dipping is particularly useful for porous carrier materials, and comprises carrier material is mixed with the solution of only enough filling the carrier micropore.

Can under decompression, atmospheric pressure or high pressure, use known method to carry out drying, comprise spray-drying and freeze drying.The temperature of drying steps is preferably≤and 200 ℃, more preferably≤160 ℃, thereby make the early stage minimum degradation of metal nitrate.Can be at air or another kind of oxygen-containing gas, or carry out drying steps under inert gas such as nitrogen, helium or the argon gas.

Therefore the metal nitrate of load will comprise one or more metal nitrates on the carrier surface or in micropore.

By metal nitrate being heated to the decomposition temperature that it forms metal oxide, or be heated to this if desired more than the temperature, cause its decomposition thereby metal nitrate is heated.This heating steps is different with drying steps (it mainly acts on is to remove to desolvate), and it changes into corresponding metal oxide by causing the metal nitrate physical-chemical.Should be appreciated that in the method for the invention, if desired, can be in single operation that the metal nitrate of load is dry and be heated to decomposition.Thereby cause the temperature of its decomposition to be 100-1200 ℃ the rising of metal nitrate temperature, but preferably this temperature is 200-600 ℃, thereby guarantees that nitrate changes into oxide, at utmost reduce the sintering of oxide simultaneously.Have been found that by at for example 200-450 ℃, particularly calcine under 200-300 ℃ the lower temperature, can obtain less metal oxide crystallite.Yet, wish wherein on carrier or form spinelle or perovskite oxide together mutually that the temperature of using 500-1200 ℃ may be desirable with carrier.The time of the metal nitrate of load under these range temperature is preferred＜and 16 hours, more preferably＜8 hour.Most preferably short calcination time, for example≤4 hour, especially≤2 hour.

Preferred 90wt% at least, more preferably 95wt% at least, most preferably the metal nitrate of 99wt% changes into corresponding metal oxide at least.

The invention is characterized in that the atmosphere that the metal nitrate of load during heating exposes comprises seldom or do not contain free oxygen, described free oxygen is considered to a reason of metal oxide poor dispersion in the nitrate derived material.Therefore contain oxygen (O in the air-flow ₂) measure by volume＜5%, preferred＜1%, most preferably＜0.1%.

The air-flow that metal nitrate exposes can be to comprise nitric oxide and have＜any air-flow of 5 volume % oxygen.Preferred this air-flow comprises that one or more are selected from the gas of carbon monoxide, carbon dioxide or inert gas.Preferred inert gas be selected from nitrogen, helium or argon gas one or more.The air-flow that the metal oxide of preferred load exposes is made up of one or more inert gases and nitric oxide.

The admixture of gas that the metal nitrate of load exposes can typically mostly be most about 10bar absolute pressure for atmospheric pressure or more than atmospheric pressure.Can use the whole bag of tricks known in the art to carry out heating steps.For example, the reproducibility air-flow can be by the metal nitrate bed of particulate load.Wherein by the following heating steps that carries out, make the metal oxide bed of admixture of gas by load, the gas hourly space velocity of admixture of gas (GHSV) is preferably 100-600000h ^-1, 600-100000h more preferably ^-1, most preferably be 1000-60000h ^-1

Nitric oxide production concentration is preferably 0.001-15 volume % in the air-flow, and more preferably 0.01-10 volume % most preferably is 0.1-5 volume %, thereby at utmost reduces the washing demand.

Metal nitrate can be any metal nitrate, but is preferably the nitrate of the metal that is used to make catalyst, catalyst precarsor or adsorbent.Metal nitrate can be basic cu nitrate (alkali-nitrate), alkali nitrates or transition metal nitrate.Preferable alloy nitrate is transition metal nitrate, promptly is selected from the nitrate of the metal of 3-12 family in the periodic table of elements.The suitable metal nitrate that is used for the easy acquisition of catalyst, catalyst precarsor or adsorbent manufacturing comprises the nitrate of La, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu and Zn, the more preferably nitrate of Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu and Zn.

Can there be one or more metal nitrates.Term " metal nitrate " is meant and comprises formula M (NO ₃) _x(H ₂O) _aThe metal nitrate compound, wherein x be the chemical valence of metal M and ' a ' can be 0 or 〉=1 integer, and the partially decomposed product of this compounds that for example formerly forms during the drying steps is as metal hydroxy nitrate.

We find that method of the present invention is specially adapted to reducible metal oxide of production high dispersive, and promptly wherein part metals can be by using reproducibility air-flow such as carbon monoxide and/or the hydrogen reducing metal oxide to its element form at least.Therefore this reducible metal oxide comprises the oxide of Ni, Co, Cu and Fe, and in a preferred implementation, this metal nitrate is nickel, cobalt, copper or iron, more preferably the nitrate of nickel or cobalt, especially nickel.Can there be one or more metal nitrates, for example comprise Cu/Ni, Co/Ni material.

It can be metal, carbon, metal oxide, mixed-metal oxides or solid polymer support that metal nitrate can load to top carrier.For example, carrier can be the single or mixed-metal oxides that comprises silica or silicate, or is applicable to the another kind of carrier that catalyst or adsorbent are made, for example metal, metal alloy or carbon.The present invention can use one or more carriers.

Powdered, ball shape or granular form and have suitable porosity for example above carbon carrier such as activated carbon, high surface graphite, carbon nano-fiber and the fullerene of 0.1ml/g can be used as carrier of the present invention, preferably wherein air-flow comprises＜oxygen of 0.1 volume %.Use therein in the art methods of air calcination, can not use these carriers.

Preferred vector is an oxidation carrier, and it can be single or mixed metallic oxide material, comprises pottery, zeolite, perovskite, spinelle etc.Oxidation carrier also can be degree priming paint (wash-coat) form on pottery, metal, carbon or the polymer substrate.

Carrier can be surperficial weight-average diameter D[3,2] and be the powder type of 1-200 μ m.M.Alderliesten is at paper " A Nomenclature for Mean Particle Diameters "; Anal.Proc., vol 21, in May, 1984, define term surface weight-average diameter D [3,2] in the 167-172 page or leaf, perhaps be called the Sauter average diameter, and calculate according to grain size analysis, wherein said grain size analysis can for example be used Malvern Mastersizer easily, is undertaken by laser diffraction.Granularity is that the agglomerate of this class powder of 200 μ m-1mm also can be used as carrier.Perhaps carrier can be the forming unit form, is 1-25mm and length-width ratio less than 2 pill, extrudate or particle as granule size typically.(granularity is meant minimum particle size, as width, length or diameter).Perhaps carrier can be the material all in one piece form, and for example honeycomb or poromerics such as open-cell foam are constructed.

Carrier is preferably selected from aluminium oxide, metal aluminate, silica, alumino-silicate, titanium dioxide, zirconia or its mixture, comprise cogelled, itself or be powder, forming unit, material all in one piece form or be the micropore form.

Carrier can be a silica supports.Silica supports can by natural origin for example diatomite form, can be pyrolysis or fumed silica, maybe can be synthetic, for example precipitated silica or silica gel.Ordered mesoporous silicas such as SBA-15 can be used as carrier.Preferred precipitated silica.Silica can be Powdered or moulding material, for example extrudes shape, ball shape or pelletized silica piece.Suitable Powdered silica typically has surperficial weight-average diameter D[3,2] be the particle of 3-100 μ m.Shaping silica can have different shape and granularity, depends on employed mould and mould in it is made.For example particle can have the cross sectional shape and about 1 of circle, leaf or other shape to the length greater than 10mm.The BET surface area of suitable Powdered or pelletized silica is generally 10-500m ²/ g is preferably 100-400m ²g ^-1Pore volume is typically about 0.1-4ml/g, and preferred 0.2-2ml/g and average pore size are preferably the about 30nm of 0.4-.If desired, silica can mix with additional metals oxide such as titanium dioxide or zirconia.Silica or can be used as the coating on the forming unit and exist, typically as the silica dioxide coating of the 0.5-5 individual layer on the carrier below, described forming unit is preferably aluminium oxide.

Carrier can be a titania support.Titania support is synthetic preferably, for example precipitated titania.Titanium dioxide for example can randomly comprise the another kind of refractory oxide material of 20 weight % at the most, typically is silica, aluminium oxide or zirconia.Titanium dioxide or can be used as the coating on the carrier and exist, for example as the 0.5-5 individual layer coating of titanium dioxide on following aluminium oxide or the silica supports, described carrier is preferably silica or aluminium oxide.The BET surface area of suitable titanium dioxide is generally 10-500m ²/ g is preferably 100-400m ²/ g.The pore volume of titanium dioxide is preferably about 0.1-4ml/g, and more preferably 0.2-2ml/g and average pore size are preferably the about 30nm of 2-.

Similarly, Zirconia carrier can be a synthetic, for example precipitates zirconia.Zirconia for example can randomly comprise the another kind of refractory oxide material of 20 weight % at the most in addition, and described oxide material typically is silica, aluminium oxide or titanium dioxide.Perhaps zirconia can be a stabilisation, for example the zirconia of yittrium oxide or ceria-stabilised.Zirconia or can be used as the coating on the carrier and exist, for example as the zirconia coating of the 0.5-5 individual layer on following aluminium oxide or the silica supports, described carrier is preferably silica or aluminium oxide.

Carrier can be metal aluminate, for example calcium aluminate.

Carrier material can be a transition alumina.Transition alumina is at " UllmansEncyklopaedie der technischen Chemie ", and 4., neubearbeitete underweiterte Auflage, Band 7 (1974), pp.298-299 " in definition is arranged.Suitable transition alumina can be the gamma oxidation aluminium family, for example η-aluminium oxide or χ-aluminium oxide.These materials can pass through to form 400-750 ℃ of following calcinations of aluminum hydroxide, and have 150-400m usually ²The BET surface area of/g.Perhaps, transition alumina can be δ-oxidation aluminium family, comprise the high temperature form as δ-aluminium oxide and θ-aluminium oxide, it can be heated to about temperature more than 800 ℃ by γ family aluminium oxide and form.δ-family's aluminium oxide has 50-150m usually ²The BET surface area of/g.Perhaps, transition alumina can be an Alpha-alumina.Transition alumina comprises and is less than 0.5 mole of water per mole Al ₂O ₃, actual amount of water depends on the temperature that they are heated to.The surperficial weight-average diameter D[3 of suitable transition alumina powder, 2] be generally 1-200 μ m.Use at some, for example intend being used for the catalyst of slurry reaction, use on average preferably less than 20 μ m, for example 10 μ m or littler very fine particle are favourable.Use for other, for example as the catalysts that carries out in fluid bed, it is desirable using bigger granularity, and described granularity is preferably 50-150 μ m.As if preferred alumina powder has bigger average pore size, because use this aluminium oxide to make catalyst produce good especially selectivity.The average pore size of preferred aluminium oxide is 10nm at least, is in particular 15-30nm.[the term average pore size is meant under 0.98 relative pressure, and 4 times of pore volumes that measured by the absorption branch of nitrogen physisorption isotherms are divided by the BET surface area].Preferably, alumina material is gamma-alumina or θ aluminium oxide, more preferably θ aluminium oxide, and it has 90-120m ²BET surface area and the 0.4-0.8cm of/g ³The pore volume of/g.Alumina supporting material can be spraying dry powder shape or can form forming unit as sphere, ball shape, cylindricality, annular or porous pill shape, it can be leafy shape or the groove line is arranged, for example clover leaf cross section, or extrudate shape well known by persons skilled in the art.Can advantageously select the alumina support of high filterability and wear resistence.

The present invention can be used to transform the metal nitrate on any carrier material, however more preferably specific metal nitrate/support combinations.For example, depend on metal, may need or may not need metal nitrate is combined with carrier that described carrier is being used to make under the heating condition of metal nitrate decomposition, can form the mixed-metal oxides compound with the metal oxide of the load that obtains.Can use low-activity supports such as carbon or Alpha-alumina to reduce or prevent and form undesirable mixed-metal oxides with carrier.

As mentioned above, we find that method of the present invention is particularly useful for making reducible metal oxide of high dispersive on carrier.Therefore in one embodiment, this method further is included in reducible metal oxide of heating load under the reproducibility air-flow, thereby realizes the reduction of at least a portion metal oxide.Can use any reproducibility air-flow, yet preferred reproducibility air-flow comprises carbon monoxide and/or hydrogen.

Therefore the present invention also provides a kind of metal oxide of reduction of the load that can obtain by said method.The metal oxide of the reduction of load will comprise the metal of element state on carrier material, and may comprise unreduced metal oxide.In addition, can exist on the carrier other, reducible or non-reducible metal oxide.

In this embodiment, the metal oxide of load comprises at least a reducible metal oxide; Be preferably selected from one or more of nickel oxide, cobalt oxide, cupric oxide or iron oxide, and preferably use hydrogen-containing gas to reduce.

Therefore reduction step can be carried out through reducible metal oxide of overload by the mixture that at high temperature makes hydrogen-containing gas such as hydrogen, forming gas or hydrogen and nitrogen, methane or other inert gas, for example by at atmospheric pressure or at the most approximately under the high pressure of 25bar, at 150-600 ℃, under preferred 300-500 ℃ the temperature, make hydrogen-containing gas through composition 0.1-24 hour.The best reducing condition of nickel oxide, cobalt oxide, cupric oxide or iron oxide is known for those skilled in the art.

In metal oxide by the reduction of the load of the inventive method preparation, preferably can be with at least 70%, more preferably＞80% and reducible metal oxide most preferably＞90% be reduced into the element activity attitude.Can obtain to have the metal oxide of the reduction that high metal disperses by method of the present invention, it is expressed as the metal surface area of every gram catalyst or every gram metal in reducing material.Metal surface area can be recorded by chemisorbed (for example hydrogen chemisorbed) easily by using method known to those skilled in the art.

Compare with the metal oxide that uses art methods to obtain and the metal oxide of reduction, the metal oxide of this load and the metal oxide of reduction have very high metal oxide and metal disperses.This be because have＜air-flow of 5 volume % oxygen in, the decomposition of the metal nitrate in the presence of nitric oxide has prevented the metal oxide sintering, otherwise will produce sintering.

Have been found that by scanning transmission electron microscopy (STEM) and X-ray diffraction (XRD), loading on the carrier at the most on the metal oxide of 30 weight % of obtaining, the metal oxide crystallite dimension of the metal oxide of load of the present invention is less than 10 nanometers, preferably less than 5 nanometers.The crystallite dimension of the metal oxide of the reduction of load also＜10nm, preferred＜5nm.

The metal oxide of the metal oxide of load and the reduction of load can be used for many technical fields.These fields comprise catalyst, catalyst precarsor, adsorbent, semiconductor, superconductor, magnetic storage medium, solid storage medium, pigment and UV absorbent.Preferably with the metal oxide of the reduction of the metal oxide of load and load as catalyst, catalyst precarsor or adsorbent.Term " adsorbent (sorbent) " comprises adsorbent (adsorbent) and absorbent (absorbent).

The for example Cu oxide of Hai Yuan load such as Cu/ZnO/Al ₂O ₃As methanol synthesis catalyst and water-gas shift catalyst.Ni, the Cu of load of reduction and Co oxide can be separately or with other metal oxide for example zinc oxide combine catalyst as hydrogenation, and the Fe that reduces or Co oxide can be used as the Fischer-Tropsch catalyst of hydrocarbon.It is synthetic that the Fe catalyst of reduction also can be used for high temperature transfer reaction neutralization of ammonia.

In preferred embodiment, the metal oxide of the metal oxide of load and the reduction of load is the catalyst in synthetic as the Fischer-Tropsch of hydrogenation and hydrocarbon.These catalyst can also comprise that except Ni, Cu, Co or Fe one or more are used for the appropriate addn and/or the promoter of hydrogenation and/or Fischer-Tropsch catalysis.For example, Fischer-Tropsch catalyst can comprise that one or more change the additive of physical properties and/or influences catalyst reduction or activity or promoter optionally.Suitable additive is selected from the compound of following metal, and described metallic compound is selected from potassium (K), molybdenum (Mo), nickel (Ni), copper (Cu), iron (Fe), manganese (Mn), titanium (Ti), zirconium (Zr), lanthanum (La), cerium (Ce), chromium (Cr), magnesium (Mg) or zinc (Zn).Suitable promoter comprises rhodium (Rh), iridium (Ir), ruthenium (Ru), rhenium (Re), platinum (Pt) and palladium (Pd).One or more promoter that are preferably selected from Ru, Re, Pt or Pd are included in the catalyst prerequisite.Can pass through to use suitable compound, for example sour as perrhenic acid, slaine, for example metal nitrate or metal acetate, perhaps suitable metallo-organic compound, for example metal alkoxide or metal acetylacetonates join additive and/or promoter in the catalyst.Based on reducible metal, the amount of promoter metals is 3-50 weight %, is preferably 5-20 weight %.

As mentioned above, the metal oxide catalyst of the reduction of load can for example be used for hydrogenation, particularly Ni and Co catalyst and be used for the Fischer-Tropsch of hydrocarbon synthetic, particularly Co and Fe catalyst.

Typical hydrogenation comprises that hydrogenation of aldehydes and nitrile are alkohol and amine and hydrogenation of cyclic aromatic compounds or unsaturated hydrocarbons respectively.Catalyst of the present invention is specially adapted to the hydrogenation unsaturated organic compound, and particularly oil, fat, aliphatic acid and derivative of fatty acid are as nitrile.Typically in continuous or mode intermittently, by in autoclave, under pressure, under the temperature of environment or rising, in the presence of Co catalysts, handle the compound for the treatment of hydrogenation with hydrogen-containing gas, thereby carrying out this hydrogenation, can be 0.1-5.0 * 10 with scope at 80-250 ℃ for example ⁶Carry out hydrogenation with hydrogen under the pressure of Pa.

The Fischer-Tropsch of hydrocarbon is synthetic to be well-known.The synthetic mixture with carbon monoxide and hydrogen of Fischer-Tropsch is converted into hydrocarbon.Carbon monoxide and hydrogen mixture typically is hydrogen: the ratio of carbon monoxide is 1.7-2.5: 1 forming gas.Can in continuous or technology intermittently, use slurry-phase reactor, bubble-column reactor, annular-pipe reactor or the fluidized-bed reactor of one or more stirring to react.Can be this technology of operation under the pressure of 0.1-10Mpa and the temperature that scope is 150-350 ℃ in scope.For continued operation, gas hourly space velocity (GHSV) scope is 100-25000h ^-1Catalyst of the present invention is owing to their high metal surface area/g catalyst has particular utility.

Further specify the present invention by reference the following example with reference to figure 1-7, wherein:

Fig. 1 has described the XRD figure case of (a) silicon dioxide carried cobalt oxide (A-1) prepared in accordance with the present invention and silicon dioxide carried cobalt oxide (A-2) not prepared in accordance with the present invention, (b) silicon dioxide carried nickel oxide (B-1 prepared in accordance with the present invention, C-1) and silicon dioxide carried nickel oxide (B-2 not prepared in accordance with the present invention, C-2) XRD figure case

Fig. 2 described silicon dioxide carried cobalt oxide (A-1, A-2) and silicon dioxide carried nickel oxide (B-1, B-2, C-1, bright visual field STEM microphoto C-2),

Fig. 3 described silicon dioxide carried cobalt oxide (A-1, nitrogen physisorption isotherms A-2),

Fig. 4 has described (a) silicon dioxide carried nickel oxide B-1, B-2 and (b) silicon dioxide carried nickel oxide C-1, and the nitrogen physisorption isotherms of C-2,

Fig. 5 has described the XRD figure case of silicon dioxide carried cobalt oxide (D-1) prepared in accordance with the present invention and silicon dioxide carried cobalt oxide (D-2) not prepared in accordance with the present invention, (b) the XRD figure case of silicon dioxide carried nickel oxide (E-1) prepared in accordance with the present invention and silicon dioxide carried nickel oxide (E-2) not prepared in accordance with the present invention

Fig. 6 described silicon dioxide carried cobalt oxide (D-1, D-2) and silicon dioxide carried nickel oxide (E-1, bright visual field STEM microphoto E-2),

Fig. 7 has described conversion ratio % and the C1﹠amp with respect to the time at the catalyst D-1 that tests in the synthetic hydrocarbon with laboratory scale by fischer-tropsch reaction; The C5+% selection rate,

Fig. 8 is according to catalyst D-1 and the D-2 time productive rate (mol with respect to the cobalt of catalyst reduction temperature _COGCo ^-1S ^-1), described by fischer-tropsch reaction with laboratory scale the catalyst activity in the synthetic hydrocarbon,

Fig. 9 has described the XRD figure case according to the nickel oxide catalyst on silica (F-1) of the contrast of open method preparation among the EP0421502,

Figure 10 described comparative catalyst F-1 bright visual field STEM microphoto and

Figure 11 has described the nitrogen physisorption isotherms of comparative catalyst F-1.

The nickel oxide and the cobalt oxide of embodiment 1:SBA-15 load

At SBA-15 powder (BET surface area=637m ²g ^-1, total pore volume=0.80cm ³g ^-1) upward use the cobalt nitrate (II) of variable concentrations or nickel nitrate (II) aqueous solution to carry out just wet impregnation steps, thereby obtain the Co/SiO of 15wt% ₂The Ni/SiO of (sample A) and 12wt% and 20wt% ₂(sample B and C).After 15 minutes equilibration time, by with 1 ℃ of min ^-1The rate of heat addition with sample from 25 ℃ of final temperatures that are heated to 70 ℃ (sample A) and 120 ℃ (sample B and C), with the dipping solid drying.Sample was kept 720 minutes under final temperature.In plug flow reactor (diameter 1cm, length 17cm), a small amount of (60mg) sample A, B and C are carried out secondary heat treatment, in the helium flow that contains 1 volume % nitric oxide (NO) or in air (i.e. calcining), with 1 ℃ of min ^-1The rate of heat addition be heated to 450 ℃ and kept 240 minutes from 25 ℃ at 450 ℃.Heat treated sample is expressed as A-1, B-1 and C-1 in the helium flow that contains 1 volume % nitric oxide (NO) according to the present invention, and air calcination sample not according to the present invention is expressed as A-2, B-2 and C-2.Preparation condition is summarised among the table 1-3.

Table 1: immersion condition

	Cobalt (A)	Nickel (B and C)
			Carrier amount (g)	0.25	0.25
Precursor	Co(NO 3) 2·6H 2O	Ni(NO 3) 2·6H 2O
			Precursor solution concentration (M)	3.01	1.26 (B) with 4.23 (C)
Dipping	60mbar is just wet without spin	60mbar is just wet without spin
			Equilibration time (min)	15	15

Table 2: drying condition

	Cobalt (A)	Nickel (B)
			Initial temperature (℃)	25	25
Final temperature (℃)	70	120
			The rate of heat addition (℃ min -1)	1	1
In the time of final temperature (min)	720	720
			Atmosphere	Air	Air

Table 3: the description of the air temperature and current of secondary heat treatment

Step N °	Duration (min)	T Initial (℃)	T Finally (℃)	The rate of heat addition (℃ min -1)	He (ml min -1)	NO/He* or air (ml min -1)
							1	10	25	25	0	90	0
2	425	25	450	1	0	90
							3	240	450	450	0	0	90
4	45	450	25	-10	90	0

^*Premixed gas bottle concentration is 1v/v%NO/He

Use X-ray powder diffraction (XRD), scanning transmission electron microscopy (STEM) and nitrogen physisorption to characterize sample A-1, B-1, C-1, A-2, B-2 and C-2.Use Co-K _{α 12}(

) radioactive ray, at room temperature obtain the XRD figure case by Bruker-Nonius D8 Advance X-rayDiffractometer device from 35-80 ° of 2 θ.The maximum intensity reflection of use in 2 θ=43.1 and 50.8 °, according to the Scherrer formula [referring to Scherrer, P.

Nachrichten 2 (1918) 98] calculate the average crystalline size of cobalt oxide and nickel oxide respectively.The Tecnai 20FEG microscope that use moves under 200kV obtains the STEM image.Measure the particle mean size of cobalt oxide and nickel oxide by 50 particle diameters typically.

Under 77K, use Micromeritics Tristar 3000 measurement device nitrogen physisorption.Before analyzing, in helium flow with sample in 120 ℃ of dryings 14 hours.Use respectively the BET method measure surface area and total pore volume [referring to Brunauer, S.; Emett, P.H.andTeller, E.J.Am.Chem.Soc.60 (1938) 309] and the nitrogen amount that under 0.995 relative pressure, adsorbs.Use standard BJH theory [referring to Barret, P.; Joyner, L.G.; Halenda, P.P.J.Am.Chem.Soc.73 (1951) 373] by isothermal absorption branch calculated hole diameters size distribution.

The XRD figure case of describing among Fig. 1 shows, when heat treatment in air (calcining) sample A, B and C, has formed big Co ₃O ₄With the NiO crystallite.Yet, when the method according to this invention is handled dry sample A, B and C, formed very fine Co ₃O ₄With the NiO crystallite.The contrast of average crystallite size is listed in the table 4.

Table 4: the general introduction of the average crystallite size of cobalt oxide and nickel oxide

Sample	Gas composition heat treatment	d XRD(nm)	d TEM(nm)
				A-1	NO/He	5	4-5
A-2	Air		10					10-100 ＊
				B-1	NO/He	3	#
B-2	Air	9	7-40 ＊
				C-1	NO/He	4	4-5
C-2	Air	10	8-60 ＊

^*Crystallite major part in SBA-15 micropore inside is anisotropic

^#The NiO particle diameter is too little so that can not measure

The typical bright visual field STEM image (Fig. 2) of sample A-1, A-2, B-1, B-2, C-1 and C-2 shows, kept the pore structure of the SBA-15 that formed by the opening mesopore.Microphoto clearly illustrates that the sample (A-2, B-2 and C-2) via the calcination processing preparation produces the material of SBA-15 load, and described material has the cobalt oxide and the nickel oxide particle of non-homogeneous dispersion and distribution among whole SBA-15 mesopore.In addition, microphoto shows the most of cobalt oxide that exists in the SBA-15 mesoporous channels inside and nickel oxide particle are subjected to the mesopore hole wall aspect one-dimensional growth restriction, and described hole wall produces the anisotropic particle that stops up the SBA-15 hole.In addition, the STEM image of these samples shows cobalt oxide and the nickel oxide particle of existence greater than the aperture.This represents that these particles are positioned on the carrier outer surface region.

Yet the STEM image of sample prepared in accordance with the present invention (A-1, B-1 and C-1) clearly illustrates that this step produces the cobalt oxide and the nickel oxide particle of high dispersive, and described uniform particles is distributed among the whole SBA-15 hole.In addition, do not find cobalt oxide and nickel oxide particle in the carrier outer surface region.The contrast of the cobalt oxide of sample A-1, A-2, B-1, B-2, C-1 and C-2 and the size distribution of nickel oxide is listed in the table 4.

The nitrogen physisorption isotherms of sample A-1 (Fig. 3) comprises all characteristic features that SBA-15 has, and this shows that method of the present invention do not damage its structure.Show that with the isothermal contrast of calcination sample A-2 the latter has observed the forced closed (forced closure) of desorption branch except the characteristic feature of SBA-15.This forced closed is to cause owing to mesoporous channels that the cobalt oxide crystallite blocks SBA-15.These cobalt oxides stop up the hole that produces the ink bottle type, and this causes observing isothermal forced closed during desorption.In the thermoisopleth of sample A-1, lack this feature and confirm in addition, formed very fine cobalt oxide crystallite, because do not exist even as big as blocking the crystallite of SBA-15 mesopore by method of the present invention.

Ni/SiO ₂Sample and Co/SiO ₂The contrast of the nitrogen physisorption isotherms of sample shows the similar trend of having observed, promptly the hole of observing the SBA-15 mesopore when preparing the nickel oxide material of SBA-15 load by calcining is blocked, and the application of the inventive method causes the normally closed of desorption branch, with contain not the mesoporous channels of blocking that SBA-15 expected was the same.

Embodiment 2: the cobalt oxide of silica gel load and nickel oxide

Use the cobalt nitrate (II) or nickel nitrate (II) aqueous solution dipping Davicat SI 1404 silica gel (BET surface area=540m ²g ^-1, total pore volume=0.90cm ³g ^-1), thereby obtain the Co/SiO of 18wt% ₂The Ni/SiO of (sample D) or 24wt% ₂(sample E).Aging after 15 minutes, by using the heat treatment identical with sample D and E drying with embodiment 1.In plug flow reactor (diameter 1cm, length 17cm), a small amount of (100mg) sample D and E are carried out secondary heat treatment, in the helium flow that contains 1 volume % nitric oxide (NO) or in air, with 1 ℃ of min ^-1The rate of heat addition be heated to 450 ℃ and kept 240 minutes down from 25 ℃ at 450 ℃.Under helium, make sample be cooled to 25 ℃ then.Heat treated sample D and E partly are expressed as D-1 and E-1 in the air-flow that comprises the helium that contains 1% volume nitric oxide (NO) according to the present invention, and not according to the present invention, the part of calcining is expressed as D-2 and E-2 in air stream.Preparation condition is summarised in the table 2,3 and 5.Use XRD and STEM to characterize sample.

Table 5: immersion condition

	Cobalt (D)	Nickel (E)
			Carrier	Davicat SI 1404 ＊	Davicat SI 1404 ＊
Carrier amount (g)	1	1
			Solvent	Deionized water	Deionized water
Precursor	Co(NO 3) 2·6H 2O	Ni(NO 3) 2·6H 2O
			Precursor solution concentration (M)	3.01	4.23
Dipping	The 60mbar pore volume without spin	The 60mbar pore volume without spin
			Equilibration time (min)	15	15

^*Can buy from Grace Davison on the market, average pore size is 6.5nm.

The XRD figure case of sample D-1, D-2, E-1 and the E-2 that describes in Fig. 5 shows, formed with embodiment 1 in sample A-1, A-2, B-1, B-2, C-1 and the viewed identical cobalt oxide of C-2 and nickel oxide phase, i.e. Co ₃O ₄And NiO.The diffraction pattern of sample D-1 and E-1 shows and has formed little cobalt oxide and nickel oxide crystallite, and the sample D-2 of calcination and E-2 comprise big cobalt oxide and nickel oxide crystallite.Average crystallite size is listed in the table 6.

Table 6: the general introduction of the average crystallite size of cobalt oxide and nickel oxide

Sample	Gas composition heat treatment	d XRD(nm)	d TEM(nm)
				D-1	NO/He	5	4-5
D-2	Air	11	8-60
				E-1	NO/He	4	3-4
E-2	Air	15	20-80

The typical bright visual field STEM image that exists among Fig. 6 confirms to have the XRD result of the cobalt oxide and the nickel oxide crystallite of high dispersive in sample D-1 that handles according to the present invention and E-1.In addition, cobalt oxide and nickel oxide crystallite are evenly distributed among the whole carrier.The particle mean size of observed cobalt oxide and nickel oxide is listed in the table 6.

Embodiment 3: from the catalyst of carbon monoxide and Hydrogen Preparation hydrocarbon

Prepare the process of hydrocarbon at the mixture from carbon monoxide and hydrogen, test comes from the catalytic activity of the cobalt oxide catalyst sample D-1 on silica gel of embodiment 2.Before test, in the helium flow that contains 33vol% hydrogen, sample was reduced 120 minutes down at 450 ℃.Reducing condition is summarised in the table 7.

Table 7: reducing condition

Step N °	Duration (min)	T Initial (℃)	T Finally (℃)	The rate of heat addition (℃ min -1)	Helium (ml min -1)	Hydrogen (ml min -1)
							1	85	25	450	5	40	20
2	240	450	450	0	40	20

Using plug flow reactor (diameter 0.5cm, length 4cm) under 1bar and 220 ℃, is 2 and GHSV ≈ 6500h with hydrogen/carbon monoxide volume ratio ^-1Carry out the catalytic activity test.In order to obtain the isothermal plug flow conditions, small amount of sample (20.5mg) is mixed with 250mg SiC particle (0.2mm).Use the air-flow of gc analysis output.According to these results, calculate for methane (C ₁/ C _Tot) and chain length be 5 or higher (C ₅₊/ C _Tot) the weight selection rate of product.Fig. 7 has shown in the result who reacts record in initial 15 hours.Obvious sample D-1 prepared in accordance with the present invention has high overall activity.Although it is the high capacity amount of 18wt%Co, (GSHV=34000h under 2% carbon monoxide transforms ^-1) obtained 3.44 * 10 ^-5Mol _COG _CoThe time productive rate of the good cobalt of s.

Embodiment 4: from carbon monoxide and Hydrogen Preparation hydrocarbon

Prepare the process of hydrocarbon the catalytic activity of a small amount of (the about 20 milligrams) cobalt oxide catalyst on silica gel of test at mixture from carbon monoxide and hydrogen.As the description of embodiment 2, according to the present invention (sample D-1) or in air conventional calcining (sample D-2) prepare catalyst.Before test, uses different final temperatures and contain the helium flow of 33% volume hydrogen, sample in-situ reducing 120 minutes.Use 5 ℃ of min ^-1The rate of heat addition sample is heated to final temperature from room temperature.The detailed description of reducing condition is summarised in the table 8.Use the final reduction temperature of 350 ℃, 400 ℃, 450 ℃, 500 ℃, 550 ℃ and 600 ℃ to produce a series of sample D-1.Use the final reduction temperature of 350 ℃, 450 ℃ and 550 ℃ to prepare a series of sample D-2.

Table 8: reducing condition

Step N °	Duration (min)	＊ T Finally (℃)	The rate of heat addition (℃ .min -1)	Helium (ml.min -1)	Hydrogen (ml.min -1)
						1	Change	350-600	5	40	20
2	120	350-600	0	40	20

^*Use the final temperature of 350 ℃, 400 ℃, 450 ℃, 500 ℃, 550 ℃ and 600 ℃

Use the volume ratio of plug flow reactor (diameter 0.5cm, length 4cm) and hydrogen/carbon monoxide=2, under 1bar and 220 ℃, carry out catalytic activity and test.In order to obtain the isothermal plug flow conditions, a small amount of (20mg) sample of general and 250mg diameter are that the silicon-carbide particle of 0.2mm mixes.Use the air-flow of gc analysis output.According to these calculated activity as a result.Activity is defined as the carbon monoxide molal quantity that every gram cobalt per second transforms, and is known as cobalt time productive rate (CTY).

Fig. 8 has shown the active result who obtains after the conversion of reaction in initial 18-22 hour and 2-3%.The result of sample D-1 prepared in accordance with the present invention clearly illustrates that, when 350 ℃ were increased to 550 ℃, activity was increased to largely at reduction temperature.Since 350 ℃-550 ℃ reduction temperature, observe CTY from 0.84 * 10 ^-5Mol _COG _Co ^-1S ^-1Be increased to 6.29 * 10 ^-5Mol _COG _Co ^-1S ^-1Further temperature is increased to 600 ℃, makes activity be reduced to 5.39 * 10 ^-5Mol _COG _Co ^-1S ^-1

Show that via the catalytic result that also the sample D-2 of reduction preparation obtains under 350,450 and 550 ℃ subsequently of conventional calcining in air the activity increase when the increase reduction temperature is fewer.Reduction temperature is increased to 550 ℃ from 350 ℃ and only causes CTY from 1.32mol _COG _Co ^-1S ^-1Be increased to 2.41mol _COG _Co ^-1S ^-1In the sample D-1 of 550 ℃ of reduction and showing of D-2 more clearlyly, higher more than 2 times than the catalyst (sample D-2) of conventional preparation as the effect of the present invention of sample D-1 activity.

Embodiment 5: the catalyst that is used for soya-bean oil hydrogenation

The 24wt%Ni catalyst (catalyst E-1) of the method according to this invention preparation on silica described as embodiment 2.Take by weighing required catalytic amount and put into glass container, and depress 400-450 ℃ of reduction 1 hour in atmospheric hydrogen.The catalyst of reduction is transferred in the soybean oil of hydrogenation test.

In the hydrogenation test, use iodine number (IV) is 133 soybean oil.The reducing catalyst of 200g oil and aequum is encased in hydrogenation reactor sealing, that stir.Mixture is heated to 140 ℃ and spray hydrogen by slurry under the 3bar absolute pressure.With 2 ℃/min temperature is elevated to 200 ℃ and remain under this temperature.Monitoring absorbs amounts of hydrogen in the oil, in case and IV fall to 79 then stop test.To reach hydrogenation time the measuring of 79IV as catalyst activity.This result and the comparative catalyst's that calcines in air result shows below:

Table 9: hydrogenation test result

Catalyst	Consumption (g)	Hydrogenation time (min)	Stop IV (gl 2/100g)	Transform (%)	Fusing point (℃)
						Contrast	0.0706	148	79.0	34.8	45.4
E-1	0.0707	101	79.2	37.7	45.0

The result shows by method of the present invention and has prepared quite highly active catalyst.

Embodiment 6: the Co catalyst on aluminium oxide

According to the Co catalyst that is prepared as follows the 20wt% on aluminium oxide.Use comprises 25.04gCo (NO ₃) ₂6 (H ₂O) and the heated solution of 4.95g deionized water, gamma-alumina powder (the BET 148m by just wet infusion process dipping 20.05g ²/ g, pore volume 1.04ml/g).Under 110 ℃ with impregnated powder for drying 30 minutes, then under the helium flow that contains 1 volume %NO (flow velocity is 35L/h and 40L/h), in 1 hour (2 ℃/minute of the rates of heat addition) of 240 ℃ of calcinings.In order to contrast, to flow down at the air that equates and to calcine.Calcined material is carried out XRD measure, thus the crystallite dimension of mensuration cobalt oxide.Also use hydrogen under 425 ℃, the catalyst according to the invention precursor to be reduced, and use its Co surface area of hydrogen chemistry determining adsorption down at 150 ℃ according to known method.The results are shown in the table 10.

Table 10: by the cobalt oxide crystallite dimension of XRD acquisition

Gas	Flow velocity (L/h)	Calcination temperature (℃)	The calcination time (h)	Cobalt crystallite dimension (nm)	Co SA (m 2/ g catalyst)
						He/NO	35	240	1	10.5	10.9
He/NO	40	240	1	8.8	12.4
						Air	35	240	1	12.9
Air	40	240	1	13.0

The result shows, compares with the air calcination of same material, thereby has reduced the cobalt oxide crystallite dimension effectively and increased the Co surface area that obtains according to method for calcinating of the present invention.

The comparative example: during the aerial calcining, the nickel oxide of the SBA-15 load by the preparation of purge atmosphere not

Being used to of this experiment shows that the present invention is with respect to the disclosed validity of EP0421502.

Use 4.23moll ^-1Nickel nitrate (II) aqueous solution dipping quantity is the SBA-15 powder of 0.25g, and the BET surface area of described powder is 637m ²g ^-1With total pore volume be 0.80cm ³g ^-1Thereby, obtain the Ni/SiO of 20wt% ₂(sample F).After 15 minutes equilibration time, impregnated solid is transferred to oven trays (volume 0.062dm ³, height 4cm, diameter 6cm) in, and by 1 ℃ of min ^-1The rate of heat addition sample is heated to 120 ℃ final temperature and drying from 25 ℃.Sample was kept 720 minutes under final temperature.Subsequently, lid is put on the oven trays, and in air, passes through with 1 ℃ of min ^-1The rate of heat addition sample is heated to 450 ℃ and kept 240 minutes down at 450 ℃ from 25 ℃, sample is carried out after-treatment (i.e. calcining).Therefore, during calcination processing, the sample atmosphere is not carried out effective purge.Sample is expressed as F-1.

The XRD figure case of sample F-1 is described among Fig. 9.Diffraction pattern shows when in the air atmosphere of sample F at purge not yet in effect during heat treatment, has formed very large nickel oxide (NiO) crystallite.The average crystallite of observed sample F-1 is of a size of 32nm.

The typical bright visual field STEM image of sample F-1 is presented among Figure 10.Electron micrograph shows during preparation process, has kept orderly SBA-15 central hole structure.In addition, this image shows that calcination processing has produced the sample that nickel oxide particle wherein is non-uniformly distributed in the carrier and has wide Size Distribution.In more detail, the big nickel oxide particle with 25-200nm size is present in the outer surface of SBA-15 particle.In addition, find to have anisotropic nickel oxide particle in the inside of carrier mesoporous channels.As if the growth of the particle of back one class be subjected to the restriction of mesoporous support wall.

The absorption branch (in Figure 11) of the nitrogen physisorption isotherms of sample F-1 comprises all characteristic features that SBA-15 has.This shows that the step in the preparation do not damage its structure significantly.Isothermal desorption branch comprises typical ink bottle type pore characteristics, promptly has forced closed under about 0.48 relative pressure.These ink bottle micropores derive from the nickel oxide crystallite that stops up the SBA-15 mesoporous channels.

Claims (18)

1. the metal nitrate with load changes into the method for the metal oxide of respective load, described method be included in comprise nitric oxide and have＜admixture of gas of 5 volume % oxygen content under heating of metal nitrate, thereby realize its decomposition.

2. according on the process of claim 1 wherein that metal nitrate is from the solution impregnation to the carrier material, thereby and before heating of metal nitrate converts it into the respective metal oxide, be dried to remove and desolvate.

3. according to the method for claim 1 or 2, wherein admixture of gas is made up of one or more inert gases and nitric oxide.

4. according to the method for claim 3, wherein inert gas is selected from nitrogen, helium or argon gas.

5. according to each method of claim 1-4, wherein the nitric oxide concentration in the admixture of gas is 0.001-15% by volume.

6. according to each method of claim 1-5, wherein the metal nitrate of load is heated to 100-1200 ℃ temperature.

7. according to each method of claim 1-6, wherein metal nitrate is a transition metal nitrate.

8. according to each method of claim 1-7, wherein metal nitrate is the nitrate of nickel, cobalt, copper or iron.

9. according to each method of claim 1-8, wherein carrier is metal, carbon, metal oxide, mixed-metal oxides or solid polymer support.

10. according to each method of claim 1-9, wherein carrier is selected from aluminium oxide, metal aluminate, silica, alumino-silicate, titanium dioxide, zirconia or its mixture.

11. according to each method of claim 1-10, wherein the metal oxide of load is reducible metal oxide, described method further is included in the metal oxide of heating load under the reproducibility air-flow, thereby realizes the reduction of at least a portion metal oxide.

12. according to the method for claim 11, wherein the reproducibility air-flow comprises carbon monoxide and/or hydrogen.

13. according to the method for claim 11 or 12, wherein the metal oxide of load is nickel oxide, cobalt oxide, cupric oxide or iron oxide, and uses hydrogeneous gas to reduce.

14. the oxide of the load that can obtain by each method of claim 1-10.

15. the metal oxide of the reduction of the load that can obtain by the method for claim 11-13.

16. according to the oxide of the load of the method for claim 1-10 preparation purposes as catalyst, catalyst precarsor or adsorbent.

17. according to the metal oxide of the reduction of the load of the method for claim 11-13 preparation purposes as catalyst or adsorbent.

18. according to the purposes of claim 17, wherein Hai Yuan metal oxide is hydrogenation catalyst or Fischer-Tropsch catalyst.

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