CN104646018B - A kind of unsaturated aldehyde catalyst for selective oxidation and preparation method thereof - Google Patents

Abstract

The present invention relates to unsaturated aldehyde catalyst for selective oxidation, catalyst contains molybdenum, vanadium, tungsten, copper, nickel and tin element, mainly comprises by formula M o_aV_bW_cCu_dNi_eSn_fSi_gM_hO_x(I) representing, catalyst possibly together with magnesio lanthanum hexaaluminate, through kneading, molding, dry, roasting after obtains finished catalyst by 86～96% and 0.1～8% after mass percent mixing containing molybdenum, (I) of vanadium and magnesio lanthanum hexaaluminate.For producing unsaturated acids.

Description

A kind of unsaturated aldehyde catalyst for selective oxidation and preparation method thereof

Technical field

The present invention relates to a kind of unsaturated aldehyde catalyst for selective oxidation, it is adaptable to acrylic aldehyde or methylacrolein choosing The oxidation of selecting property produces corresponding unsaturated acids, and especially suitable catalysis acrolein selectivity aoxidizes acrylic acid processed.

Background technology

Industrial acrylic aldehyde or the oxidation of aldehydes reaction unit preparing corresponding unsaturated acids of metering system are mainly many Reaction tube, is ensureing that catalyst is not sintered, on the premise of service life length, improves selectivity and mesh as far as possible Product yield, conservation, if even if feed stock conversion, acrylic aldehyde, acrylic acid yield improve 0.1～0.5 Percentage point, the amount of the product obtained increases with hundreds of～thousands of tons of level, and its economic benefit is also the most considerable 's.

It is mainly molybdenum system multicomponent catalyst about propylene fraction oxidation acrolein, acrylic acid catalyst.Due to It is strong exothermal reaction that the acrylic acid reaction of acrylic aldehyde is prepared in Propylene Selectivity oxidation, so being passed through ratio in course of reaction The steam that heat is big, effectively to remove reaction heat, but the active component molybdenum in catalyst etc. are at gas such as steam Easy loss under the washing away of stream.And, under the high temperature conditions, in catalyst, part active component molybdenum is from catalyst Surface loses because of distillation.The loss of active component molybdenum cause reduce the activity of catalyst, selectivity, intensity and Service life, and molybdenum is in the deposition in response system downstream, and blocking pipeline affects the long-term operation of system.

It addition, the active component molybdenum etc. in catalyst i.e. enables and keeps not running off, basic before and after the reaction of molybdenum equal size Change is little, but through long-term operation activity compatible, phase in version easily occurs.Key component bag in catalyst Include Fe₂(MoO₄)₃、α-Bi₂(MoO₄)₃、CoMoO₄And NiMoO₄, wherein α-Bi₂(MoO₄)₃It is to live in surface Property center, plays selective oxidation effect；Fe₂(MoO₄)₃Play redox facilitation；CoMoO₄With NiMoO₄Play Stability Analysis of Structures effect.But, catalyst prepared by employing coprecipitation method is many due to component, mistake Journey is complicated, and catalyst stabilization differs, although initial activity is the highest, but inactivation is fast.Cause many components It is a lot, wherein because have that Mo-Bi-Co-Fe-O catalyst and Mo-V-O catalysqt deactivation and stability decline Change including sublimation and the irreversible crystalline phase because of local abnormal high temperature (focus) caused Mo component Deng.These factors all can cause the change of specificity of catalyst, causes the reduction of catalyst activity and shortens catalysis The service life of agent.By decaying catalyst being carried out phenetic analysis, find Fe₂(MoO₄)₃It is reduced into FeMoO₄, and α-Bi₂(MoO₄)₃It is changed into γ-Bi₂MoO₆。

Solving the problems referred to above, the patent related to is the most, such as, for suppressing the loss of molybdenum, CN1583261 Disclose a kind of gas for the gas containing unsaturated aldehyde Yu a kind of molecule-containing keto and carry out selectivity oxygen in the gas phase Changing the O composite metallic oxide catalyst of reaction, its catalyst consists of: [Mo_aV_bCu_cX_d]Y_m[Sb_e Z¹ _fZ² _g]_nO_xWherein Mo is molybdenum, and V is vanadium, and Cu is copper, and Sb is antimony, and X is at least selected from tungsten and the one of niobium Planting element, Y is at least selected from titanium, a kind of element of antimony, Z₁It is at least chosen from Fe and a kind of element of nickel, Z₂At least selected from silicon, aluminum, a kind of element of alkali and alkaline earth metal ions, a, b, c, d, e, f, g and X represents the atomic ratio number of its element, and time on the basis of a=12, b is a number of 1 to 6, and c is 0.5 to 4 A number, d is a number of 0.05 to 4, and e is a number of 0.1 to 30, and f is of 0 to 25 Number, g is a number of 0.01 to 20；X is by the number met needed for each metallic element combined oxidation state； Catalyst is made up of its each element oxide or composite oxides.

In order to improve the stability of catalyst, the open a kind of acrylic acid catalyst of CN1130172, respectively with partially Ammonium vanadate and copper nitrate, and with Low Valent Vanadium oxide and/or at a low price Cu oxide part replace ammonium metavanadate and/or Copper nitrate makees the catalyst obtained by the raw material of vanadium metal and copper or in addition to above-mentioned raw materials, uses antimony oxidation at a low price Thing and/or the catalyst that tin-oxide obtains at a low price demonstrate there is a strengthened peak (vanadium-molybdenum at d=4.00 Reactive compound is peculiar) and the V of a strength reduction is had at d=4.38₂O₅Specific peak.So, above-mentioned The catalyst obtained has the catalysis activity of raising, and long-term performance can go out stability.Similar also has patent Document 1: Japanese Unexamined Patent Publication 2002-233757 publication, patent documentation 2: Japanese Unexamined Patent Publication 8-299797 public affairs Report, patent documentation 3: Japanese Unexamined Patent Publication 9-194213 publication, patent documentation 4: Japanese Unexamined Patent Application Publication 2004-504288 Number publication；CN102066000A.

For improving the activity of catalyst, selectivity and catalyst life, CN200980112659.3 discloses one Kind comprise the coating catalyst of following components: (a) carrier, before (b) comprises molybdenum oxide or form molybdenum oxide The ground floor of body compound, (c) comprises the second layer containing molybdenum He the poly-metal deoxide of at least one other metal. The preferably molybdenum oxide of ground floor is MoO₃, the poly-metal deoxide of the second layer is many metals that formula II represents Oxide: Mo₁₂Bi_aCr_bX¹ _cFe_dX² _eX³ _fO_y.This catalyst is the application type catalyst including carrier.Invention Purpose be suppression heterogeneously catalysed partial gas phase oxidation acrylic aldehyde be acrylic acid coating catalysqt deactivation, have and change The inactivation performance entered.This invention is not expressly recited catalyst for being catalyzed propylene oxidation acrolein, propylene The reactivity worth evaluating data of acid, such as conversion ratio, selectivity, yield etc..The open one of CN87103192 The method producing composite oxide catalysts, the Mo-Bi composite oxide catalytic wherein represented with following chemical formula The production method of agent includes coherent element source compound to mix form complex in Aquo System and be combined this Thing carries out heat treatment, uses the one of the waltherite complex of (a) Bi and Na or (b) Bi, Na and X or (c) Bi and X Compound, as Bi source, at least contains required Na and/or X of part wherein in this complex: X represent Mg, Ca, Zn, Ce and/or Sm；Y represents K, Rb, Cs and/or Tl；Z represents B, P, As and/or W；A-K represents Respective atomic ratio, as a=12, b=0.5-7, c=0-10, d=0-10, c+d=1-10, e=0.05-3, f=0.01-1, G=0-1, h=0.04-0.4, i=0-3, j=0-48, k is a number meeting other element oxide state.Solve Bi Can in composite oxide catalysts homodisperse problem.Containing α-Bi in catalyst₂(MoO₄)₃、MoO₃Fe₂ (MoO₄)₃With β-CoMoO₄、y-Bi₂MoO₆And γ-Bi₂MoO₆.The open one of CN101690900A Preparing the preparation method of acrylic aldehyde and acrylic acid catalyst, catalyst is supported thing and inert alumina by active component Carrier forms；Active component mainly comprises element, selected from Mo, Bi, Co and/or Ni and Fe, also comprises The trace element such as K, Na, Rb, Cs, Mg, Ca, Zn, B, P, W；The wherein following table of active component The formula of stating represents: Mo_aBi_bCo_cNi_dFe_eX_fY_gZ_hO_iIn formula, X represents at least one of K, Na, Rb and Cs, Y represents that at least one in B, P and W, Z represent at least one in Mg, Ca, Zn.Live The ratio that property component is supported on carrier accounts for the 5-70% of overall catalyst weight；Active component is uneven distribution, CoMoO₄、NiMoO₄Aluminate Deng divalent metal is positioned at the kernel of catalyst activity component；Fe₂(MoO₄)₃ And the MoO of free state₃Invest the outer layer of kernel；And the outermost layer of active component is bismuth molybdate, formation core- The state of shell layer distributed.In active component, bivalence molybdate is mainly beta phase structure, and α phase structure is in active component Middle content is the lowest or does not exists.Catalyst has high activity and high stability.CN1280036 mono-kind produces not Saturated aldehyde and the catalyst of unsaturated carboxylic acid, described production be by make at least one be selected from propylene, isobutene., The compound of the tert-butyl alcohol and methyl tertiary butyl ether(MTBE) and oxygen molecule or the gas containing oxygen molecule carry out vapour-phase oxidation and Realize, it is characterised in that this catalyst is a kind of combined oxidation compositions, contains: (A) containing molybdenum, bismuth and Ferrum, as the composite oxides of key component, itself is known for urging that described vapor phase catalytic oxidation reacts Agent, and (B) containing cerium and zirconium as the composite oxides of key component.Catalyst has long catalytic life also Make to operate steadily in the long term to be possibly realized.Wherein component (B), is the composite oxides represented by below general formula (2): Ce_pZr_qF_rO_y.The zirconium oxide of high degree of dispersion inhibits the gathering of cerium oxide, to keep the latter in course of reaction To absorbing and discharge the promotion functions of oxygen significantly, thus accelerate the oxidation reaction of isobutene., therefore improve Catalysis activity.Additionally, further suppress component (A) composite oxides caused because of over reduction in time not Reversible activity reduces (i.e. the stability of composite oxides improves), so that catalytic life extends.This carry High catalysis activity and the catalytic life extended inhibit reaction temperature to raise in time, thus reduce molybdenum Distillation at hot spot.This catalyst is used for isobutylene oxidation.

CN102489309A discloses a kind of catalyst preparation for producing acrylic aldehyde and renovation process.Catalyst is There are the composite oxides of following atomic ratio: Mo: Bi: Co: Ni: Fe=10-14: 1.2-2.0: 4.8-5.6∶2-3∶1-2；This catalyst has a pore size distribution more concentrated, moderate total pore volume, wherein The mesopore of about 5-10nm accounts for more than the 70% of total pore size distribution, forms short and thick pore passage structure, and this feature is composed Give the anti-carbon deposition ability that catalyst is stronger, catalyst surface not easy-sintering, it is possible to extend the service life of catalyst. And the renovation process provided by the present invention, decaying catalyst carries out 1-3 days calcination processing in an oxidizing atmosphere, Catalyst activity is suitable with fresh catalyst.CN87103192 produces Mo-Bi-Na composite oxide catalysts and produces The method of product, the method includes that mixing coherent element source compound forms complex, then carries out heat treatment, near Lack the bismuth subcarbonate of the required Na of solid solution part as Bi source compound.The activity of catalyst by means of Bi and Na imports the catalyst of specific water-insoluble compound formation and is improved greatly.

CN1109803 relates to multimetal oxide compositions, and they have two phase structure and comprise molybdenum, hydrogen, and one Individual or multiple element phosphor, arsenic, boron, germanium and silicon；And relate to described compositions and prepared by catalytic gas phase oxidation Purposes in terms of methacrylic acid, improves activity and selectivity.The open a kind of poly-metal deoxide of CN1109802 Compositions, they have two phase structure and comprise molybdenum, hydrogen, one or more element phosphors, arsenic, boron, germanium and silicon And copper, improve base acrylic acid activity and selectivity.CN1298861A is then to use to add magnesium, aluminum and silicon Composite oxides.CN1321110A is the most respectively using stibium oxide and antimony acetate as activity metal composite oxide Antimony source.To solve under high-load condition, catalytic mechanical intensity is good, the problem that activity is high. The open a kind of O composite metallic oxide catalyst of CN200410048021.7, catalyst is by 1. molybdenum, vanadium, copper Main active component and the most requisite at least by antimony and the stable component of titanium and 3. nickel, ferrum, silicon, aluminum, The composite oxides of alkali metal, alkaline-earth metal composition.The most 2. and 3. it is can be in the range of 120 DEG C to 900 DEG C Composite oxides prepared by roasting.This catalyst shows the permanent stability under high activity and good selectivity. CN1121441 discloses a kind of for being existed by acrylic aldehyde or the gas containing acrolein gas and a kind of molecule-containing keto Carrying out oxidation reaction in vapour phase and produce acrylic acid catalyst, this catalyst includes (A) a kind of composite oxides, There is molybdenum and vanadium as base stock, and be suitable to by vapor phase catalytic oxidation acrylic aldehyde to produce acrylic acid, and (B) A kind of solid peracid, its acid strength (Ho) is not more than-11.93 (Ho≤-11.93).This invention uses molybdenum vanadium type composite oxygen Compound combines with a kind of acid strength solid acid less than-11.93, improves the low temperature high activity of catalyst. The open a kind of acrylic acid catalyst for producing of CN200510059468.9, is characterized in that, at following formula The oxide of the metallic element composition that MoaVbWcCudOx (1) represents and/or composite oxides are for being catalyzed In the acrylic acid catalyst for producing of agent composition, need to control tungsten and be partially the face side of this catalyst, and/or Copper is the core side of this catalyst partially, to improve catalyst activity.Tungsten is the face side of this catalyst partially, and / or copper be partially the core side of this catalyst to be difficult to accurately to control.The open a kind of propylene formoxy-of CN102039143A Change and prepare the preparation method of acrylic acid catalyst, a) preparation method of composite oxide coating: will containing Mo, The water-soluble metal salt of V, W, Cu, Sb composition is dispersed in water/organic facies mixed system in 30-100 DEG C； Keeping organic solvent and water weight ratio is 5～50%；Reaction generates composite oxides presoma serosity；Pass through again Distillation, drying, roasting prepare catalyst activity component；B) above-mentioned active component mainly comprises element, is selected from Mo, V, Cu, W, Sb one of which or several；Wherein active component following formula represents: Mo_aV_bCu_cW_dSb_eO_f, this catalyst uses the mixed system of water and lower alcohol to prepare, and catalyst has higher Specific surface area and special microstructure, there is relatively high-ratio surface and difficult drop-off, and bearing capacity can reach To 50% and more than, solve shorter problem in application type catalyst service life.

The open a kind of methylacrolein acrylic acid catalyst of selective oxidation synthesizing methyl of CN1647854, this is urged The composition formula of agent is: x (Mo₁₂P_aK_bSb_cCu_dAs_eA_fD_gQ_hO_iMo_j)/yZ, Z are that carrier dilutes heat conduction Agent；Mo, P, K, Sb, Cu and As are respectively molybdenum, phosphorus, potassium, antimony, copper and arsenic；A represent tungsten W, At least one element in vanadium V, niobium Nb, ferrum Fe and lead Pb；D represents boron, gallium Ga, indium In, germanium At least one element in Ge and silicon Si；Q represents at least one element in rubidium Rb, caesium Cs and thallium Tl, this Bright one side improves the activity and selectivity of catalyst by adding Sb, Cu and As；On the other hand pass through Add MoO₃The heat stability of catalyst, heat conductivility and mechanical strength is improved with carrier heat conduction diluent, Effectively inhibitory activity component heteropolyacid salt decomposition and reduce beds hot(test)-spot temperature, it is to avoid Mo and The loss of As, extends catalyst service life.

The open a kind of polymetal oxide materials of CN1109800: in formula, A is Mo₁₂V_aX_b ¹X_c ² X_d ³X_e ⁴X_f ⁵X_g ⁶O_x(coexisting phase), its part B comprises and has the X-ray of at least one following copper molybdate and spread out Penetrate the crystallite (giving the raw data about X-ray diffraction fingerprint in round parentheses) of pattern: Cu₃(MoO₄)₂(OH)₂(lindgrenite, the index card 36-405 of JCPDS-ICDD index (1991)), Cu₄Mo₆O₂₀(A.Moini et al., Inorg.Chem.25(21) (1986), 3782-3785), Cu₄Mo₅O₁₇ (the index card 39-181 of JCPDS-ICDD index (1991)), etc..CN1462211 relates to a kind of system Standby containing Mo, V, Cu and the method for the multiple-phase multi-metal oxide materials of other optional element.According to this Invention, at least one phase is pre-formed independently, and in the precursor material of the plastically deformable being dispersed in another phase. Then this mixture is dried and calcines.Polymetal oxide materials is suitable as at catalytic gas phase oxidation organic Compound, particularly acrolein oxidation is being become in acrylic acid the active material of catalyst used. [A] p [B] q [C] r (I), phase A in multimetal oxide compositions, B and C can be unbodied and/or Crystallization.Phase B is advantageously made up of the crystallite of oxometallate, or comprises there is X-ray diffraction Pattern and and then the crystalline substance of oxometallate crystallite copper molybdate of crystal structure types of at least one following copper molybdate Body structure class α-CuMo₄[the registration card 22-242 of JCPDS-ICDD card index, (1991)], Cu₆Mo₅O₁₈[the registration card 40-865 of JCPCS-ICDD card index, (1991)], Cu_4-xMo₃O₁₂, its Middle x=0-0.25 [registration card 24-56 and 26-547 of JCPCS-ICDD card index, (1991)], etc..Should Catalyst is to improve selectivity.

Polymetal oxide materials [A] p [B] q [C] r (I) of the open a kind of formula of CN1295499 (I), with containing molybdenum, Vanadium, copper and antimony and one or more other metals specific also have the polymetal oxide materials of multicomponent structure Acrylic acid catalyst is prepared as with the gas phase catalytic oxidation reaction of acrylic aldehyde.In formula, A is Mo₁₂V_aX¹bX² _cX³ _dX⁴ _eX⁵ _fX⁶ _gO_x, B is X¹ ₇Cu_hH_iO_y, C is X₁ ⁸Sb_jH_kO_z, X₁For W, Nb, Ta, Cr and/or Ce.Promoter phase B is made up of the crystallite of these copper molybdate or micro-containing such copper molybdate Brilliant: α-CuMoO₄[the reference diffraction pattern in the index card 22-242 of JCPDS-ICDD retrieval 1991], Cu₆Mo₅O₁₈[the reference diffraction pattern in the index card 40-865 of JCPDS-ICDD retrieval 1991], Cu_4-x Mo₃O₁₂Wherein, x is the 0-0.25 [reference in index card 24-56 and 26-547 of JCPDS-ICDD retrieval 1991 Diffraction pattern], etc..Region C can have metaantimmonic acid copper Cu₉Sb₄O₁₉The crystallite of structure or Cu₄SbO_4.5Structure micro- Brilliant.CN1093950 discloses the compositions of one kind of multiple metal-oxides, including the oxidation shape as basis Mo, V, W, Cu, Ni of formula, its premise is to there is following ratio: Mo:V=12:1 between each elemental composition To 2:1, Mo:W=60:1 to 3:1, Mo:Cu=24:1 to 2:1, Cu:Ni=5:1 to 1:3.X₁It is one or more Alkali metal；X₂It is one or more alkaline-earth metal；X₃It is Cr, Mn, Ce and/or Nb；X₄It is Sb and/or Bi； X₅It is Si, Al, Ti and/or Zr.CN1387945 relate to containing Cu, Mo and at least one selected from element W, The oxo metal compound of the HT copper molybdate structure type of the element in V, Nb and Ta, its preparation method, and they In preparation, containing molybdenum, vanadium, copper and to contain having of one or more elements in elemental tungsten, niobium, tantalum, chromium and cerium many Application in the composite metal oxide material of phase structure.CN1394812 is at the catalysis gas for organic compound Phase oxidation reaction catalyst in use poly-metal deoxide, described poly-metal deoxide contain Mo, V and At least one in element W, Nb, Ti, Zr, Hf, Ta, Cr, Si and Ge, and it is former to have special three-dimensional Son arrangement.CN1500770 contains molybdenum, vanadium, copper and contains in elemental tungsten, niobium, tantalum, chromium and cerium a kind of or many Planting the composite metal oxide material having heterogeneous structure of element, they are by catalytic gas phase oxidation of acrolein system third Application in olefin(e) acid, and containing Cu, Mo and at least one element in element W, V, Nb and Ta The oxo metal compound of HT copper molybdate structure type.

It addition, under the high temperature conditions, in catalyst, part active component molybdenum loses because of distillation from catalyst surface. The mixed airflows such as acrylic aldehyde, air (oxygen), nitrogen and steam wash away the activity that also can make in catalyst Component runs off.For suppression molybdenum distillation loss cause activity decay, CN1121504 by mix copper component and There is specified particle diameter and the zirconium of specific surface area and/or titanium and/or cerium, dissipation effect and the mistake of molybdenum composition can be suppressed Degree reduction.Catalyst includes by lower formula (I) MO_aV_bW_cCu_dX_eY_f(I) oxygen of the metallic element composition represented Compound or composite oxides.CN1445020 adds a small amount of tellurium and plays stably free molybdenum trioxide and copper molybdate The effect of crystal structure, sublimation and the over reduction of molybdenum have suppressed；CN1583261 with molybdenum, vanadium, Copper, tungsten and/or niobium are key component, the composite oxides constituted with other element or its hopcalite The loss of composition catalyst suppression molybdenum.

Accordingly, it is desirable to provide unsaturated aldehyde selective oxidation prepares unsaturated acids catalyst, catalyst activity component Molybdenums etc. not easily run off, and activity is not susceptible to phase in version mutually, make acrylic aldehyde long period stably selective oxidation Produce acrylic acid, improve selectivity and the yield of purpose product as far as possible, to obtain bigger economic benefit.

Summary of the invention

For solving the problems referred to above, the present invention provides the preparation method of a kind of unsaturated aldehyde catalyst for selective oxidation, It is mainly used in acrylic aldehyde or metering system is oxidation of aldehydes prepares corresponding unsaturated acids, particularly suitable acrolein selectivity oxygen Metaplasia produces acrylic acid.

The present invention relates to a kind of unsaturated aldehyde selective oxidation catalyst producing unsaturated acids and preparation method thereof, Catalyst contains molybdenum, vanadium, tungsten, copper, nickel and tin element, mainly comprises and is represented by following logical formula I, urges Agent is possibly together with magnesio lanthanum hexaaluminate, containing molybdenum, (I) of vanadium and magnesio lanthanum hexaaluminate by 90～98% and 0.1～10 After kneadings, molding, dry, roasting, finished catalyst is obtained after the mixing of % mass percent.

Mo_aV_bW_cCu_dNi_eSn_fSi_gM_hO_x(I).

Wherein: Mo is molybdenum, V is vitriol, and W is tungsten, and Cu is copper, and Ni is nickel, and Sn is stannum, and Si is silicon, Silicon is the carrier added, and M is at least one element in caesium, lanthanum, manganese；O is oxygen；a、b、c、d、 E, f, g, h represent each Elements Atom ratio respectively, and wherein a=12, b are numbers of 2～8, preferably 3～6； C is a number of 0.5～7, preferably 1.0～4；D is a number of 1～6, preferably 1.0～4；E is 0.5～4 One number, f is a number of 0.1～2, and g is a number of 0.5～50, preferably 1～20, and h is 0.05～2 One number, x is the numerical value determined by the oxygen of each oxide.

The present invention is with leading to the preferred lanthanum of M in the catalyst activity component that formula I represents, lanthanum and nickel, copper, stannum Etc. stable crystal phase structure can be formed, such as Cu₂La、LaNi₅、La₂Ni₇, LaSn etc., thus suppressing portion Point active component molybdenum loses because of distillation from catalyst surface, and active component molybdenum not easily runs off, and delays activity deterioration Speed, catalyst activity and good stability.With molybdenum, vanadium ratio suitably, in logical formula I, h is 0.05～2 to lanthanum One number.The preferred Lanthanum (III) nitrate in lanthanum source of the present invention, the preferred sodium stannate of Xi Yuan, stannous chloride.

It is highly preferred that catalyst is 92～the catalyst (I) of 97% and quality hundred containing weight/mass percentage composition Point content is 1.5～7% magnesio lanthanum hexaaluminate.

Magnesio lanthanum hexaaluminate oxide of the present invention is prepared according to conventional coprecipitation.As used following method system Standby: by magnesium nitrate, Lanthanum (III) nitrate and aluminium hydroxide according to LaMgAl₁₁O₁₉Stoichiometric proportion mix homogeneously, add Enter deionized water and stir, being then spray-dried, gained powder through 160 DEG C be dried after through 1000～1500 DEG C Roasting 3～12 hours, then by pulverizing or the method such as ball milling obtains particle diameter magnesio six aluminic acid below 20 μm Lanthanum LaMgAl₁₁O₁₉。

The preparation method of catalyst of the present invention, prepares catalyst (I), magnesio lanthanum hexaaluminate including by coprecipitation, By catalyst (I), magnesio lanthanum hexaaluminate by 90～98% and 0.1～10% mass percent mixing after through mediate, Molding, it is dried, obtains finished catalyst after roasting.

Under Oxygen Condition, catalyst molybdenum isoreactivity component under the high temperature conditions is not only easy to run off, and activity phase Being susceptible to phase in version, activity mutually phase in version occurs so that catalyst loses activity, and causes active selectable bright Aobvious decline.Such as activity phase VMo₃O₁₁It is changed into MoO₃, CoMoO₄It is changed into Co₃O₄, CuMoO₄Turn Become MoO₃Deng.

Active component molybdenums in catalyst etc. i.e. enable holding and do not run off, and before and after the reaction of molybdenum equal size, basic change is not Greatly, but easily there is phase in version through long-term operation activity compatible.The present invention is by magnesio lanthanum hexaaluminate (LaMgAl₁₁O₁₉) add in catalyst, make active phase more stable, be not susceptible to phase in version thus Improve catalyst activity and selectivity.

The composite multi-metal oxide catalyst (I) of the present invention uses common preparation method, as adopted Prepare by following step.

Each unit that M part in compound containing Mo, V, W, Cu, Ni, Sn and logical formula I is related to Element component composition is dissolved and mix homogeneously in proportion, forms serosity, in slurry production process after being co-precipitated Adding one or more in silicon dioxide, aluminium oxide or carborundum, dry, molding, roasting obtains catalyst (I).

Catalyst of the present invention (I) and finished catalyst need roasting 3～10h at 350～500 DEG C, compare not The catalyst of roasting respectively, repeatedly roasting can improve activity and the stability of catalyst.It can be open roasting Can also be enclosed roasting, calcination atmosphere can be the noble gases such as helium, nitrogen, argon.

The compound of each component of catalyst of the present invention can use the nitrate of each element, ammonium salt, sulphuric acid Salt, oxide, hydroxide, chloride, acetate etc..As ammonium molybdate, ammonium metavanadate, ammonium paratungstate, Molybdenum oxide, copper nitrate, copper oxide, Schweinfurt green, nickel nitrate, Lanthanum (III) nitrate, cesium nitrate, potassium manganate, manganese oxide Deng.

After catalyst slurry of the present invention is dried, it is usually preferred to use extrusion molding, granulating and forming, compression molding etc. Forming method is processed into spherical, hollow spheres, ellipticity, cylindric, hollow circuit cylinder etc., preferably hollow circle Post or spherical.

Evaluating catalyst performance index definition is as follows:

Detailed description of the invention

With specific embodiment, composite multi-metal oxide catalyst and preparation method thereof, and this catalysis are described below Agent catalytic performance in acrylic aldehyde (ACR) selective oxidation prepares acrylic acid (AA), but the present invention Scope is not limited to these embodiments.The analysis method of product composition uses method generally in the art.

Embodiment 1

1. prepare catalyst (I)

Under agitation, take 211.9 grams of ammonium molybdates, ammonium metavanadate 46.8 grams, be dissolved in 500ml pure water In (water temperature more than 65 DEG C), obtain serosity (1), then take 52.2 grams of ammonium paratungstates, 127.9 grams of copper nitrates, 14.5 grams of nickel nitrates, 48 grams of sodium stannates, 5.8 grams of cesium nitrates be dissolved in 1000ml pure water (water temperature 65 DEG C with On), it is thoroughly mixed uniformly, obtains serosity (2).Then, serosity (1) mixes with serosity (2), Obtain serosity (3), i.e. obtain active component serosity (a).10.8 grams are added in active component serosity (a) Silicon dioxide powder and 1.4 grams of graphite, 80 DEG C of strong stirrings carry out coprecipitation reaction post-heating and are dried, 460 DEG C of roastings Burn 5 hours, then grind to form the fine powder of below 60 μm, prepared catalyst (I) mainly comprise into:

Mo₁₂V₄W₂Cu_5.5Ni_0.5Sn_1.8Cs_0.3Si_1.8O_x

By magnesium nitrate, Lanthanum (III) nitrate and aluminium hydroxide according to LaMgAl₁₁O₁₉Stoichiometric proportion mix homogeneously, add Enter deionized water and stir, being then spray-dried, gained powder through 160 DEG C be dried after through 1100 DEG C of roastings 10 hours, then obtain particle diameter magnesio lanthanum hexaaluminate LaMgAl below 20 μm by methods such as ball millings₁₁O₁₉。

Take catalyst (I) 94 part, magnesio lanthanum hexaaluminate 6 parts, add deionized water and mediate in kneader, The extruded hollow columnar granule for φ 4.5 × 5mm, is dried under the conditions of 120 DEG C, and at 450 DEG C, roasting 6.5 is little Time obtain catalyst 1.

Embodiment 2

The preparation of catalyst 2

Preparation process and primary raw material with embodiment 1 catalyst 1 are identical, simply add 16.2 grams of Lanthanum (III) nitrates, Catalyst (I) mainly comprises as Mo₁₂V₅W₄Cu₂Ni_3.7Sn_0.6La_0.5Si_2.2O_x.Take catalyst (I) 97 parts, magnesio lanthanum hexaaluminate 3 parts, add deionized water and mediate in kneader, through banded extruder extruding, roll It is a granulated into the ball shape of a diameter of 2mm, within 8 hours, i.e. obtains catalyst 2 through 450 DEG C of roastings.

Embodiment 3

Preparation process and primary raw material with embodiment 1 catalyst 1 are identical, simply add 11.8 grams of potassium manganates, Catalyst (I) mainly comprises as Mo₁₂V₂W_6.7Cu₁Ni_1.2Sn_1.0Si_0.7Mn_0.6O_x.Take catalyst (I) 95 parts, magnesio lanthanum hexaaluminate 5 parts, add deionized water and mediate in kneader, extruded through banded extruder be The hollow columnar granule of φ 4.5 × 5mm, i.e. obtains catalyst 3 in 6 hours through 500 DEG C of roastings.

Embodiment 4

Preparation process and primary raw material with embodiment 2 catalyst 2 are identical, catalyst (I) mainly comprise into: Mo₁₂V₈W_0.5Cu₄Ni_2.4Sn_0.1Si_1.0La_1.8O_x.Take catalyst (I) 91 part, magnesio lanthanum hexaaluminate 9 parts, Add deionized water to mediate in kneader, through the extruded hollow columnar granule for φ 4.5 × 5mm of banded extruder, Within 6 hours, catalyst 4 is i.e. obtained through 500 DEG C of roastings.

Comparative example 1

Prepare comparative catalyst 1 according to the proportioning that mainly comprises of embodiment 1, but magnesio lanthanum hexaaluminate be not with The form of solid solution, oxide adds catalyst, but prepares catalyst with coprecipitation method, and reaction condition is with urging The appreciation condition of agent 1.Comparative catalyst 1 mainly comprise for:

Mo₁₂V₄W₂Cu_5.5Ni_0.5Sn_1.8Cs_0.3Si_1.8La_0.3Si_1.5Mg_0.3Al_3.3O_x

Oxidation reaction

Fixed bed single tube reactor internal diameter 25mm, inside sets thermocouple, loads along feedstock direction reactor bed The above-mentioned catalyst of 50ml or comparative example catalyst, salt bath heating, salt temperature 250 DEG C.Pipe enters from the reactions above Mouth sentences air speed 1350h^-1Acrylic aldehyde 9 volume %, oxygen 13 volume %, steam 15 volume %, nitrogen The mixed gas of 63 volume %.React 24 hours, load beds hot localised points temperature of the present invention the highest In 276 DEG C, reaction bed temperature indexing is more reasonable, improves purpose selectivity of product and yield, propylene Acid yield more than 89.0%, after the catalyst reaction 2000h of embodiment 1 and 4, bed hot(test)-spot temperature is respectively 273 DEG C, 276 DEG C, acrolein conversion rate is respectively 99.2% and 99.1%, and acrylic acid (AA) selectivity divides It is not 91.0% and 91.3%, acrylic acid yield 89.3%, 89.4%.Steam intake 15 volume %'s In the case of, through the reaction of 2000 hours, catalyst activity component molybdenum etc. not easily runed off, and activity is the most not Phase in version easily occurs, and catalyst activity component structure is stable.During acrolein oxidation, beds temperature Degree distribution is more reasonable.Acrylic aldehyde (ACR) and acrylic acid (AA) total recovery more than 91.0%, catalyst Active component Stability Analysis of Structures, catalyst has good water repelling property, catalyst performance stabilised.Comparative example is catalyzed Agent poor selectivity, acrylic aldehyde, acrylic acid yield are low.

Table 1 reacts 24 hours post-evaluation results

Claims (8)

1. a unsaturated aldehyde catalyst for selective oxidation, catalyst contains molybdenum, vanadium, tungsten, copper, nickel and tin element, mainly comprises By formula M o_aV_bW_cCu_dNi_eSn_fSi_gM_hO_x(I) represent, catalyst possibly together with magnesio lanthanum hexaaluminate, described main group Become and magnesio lanthanum hexaaluminate by 90～98% and 0.1～10% after mass percent mixing through kneadings, molding, dry, roasting After obtain finished catalyst, wherein, silicon be add carrier, M is at least one element in caesium, lanthanum, manganese；O It is oxygen；A, b, c, d, e, f, g, h represent each Elements Atom ratio respectively, and wherein a=12, b are numbers of 2～8, C is a number of 0.5～7, and d is a number of 1～6, and e is a number of 0.5～4, and f is a number of 0.1～2, G is a number of 0.5～50, and h is a number of 0.05～2, and x is the numerical value determined by the oxygen of each oxide.

Catalyst the most according to claim 1, it is characterised in that containing the institute that weight/mass percentage composition is 92～97% in catalyst State that to mainly comprise with weight/mass percentage composition be 1.5～7% magnesio lanthanum hexaaluminate.

Catalyst the most according to claim 1, it is characterised in that in logical formula I, b is a number of 3～6.

Catalyst the most according to claim 1, it is characterised in that in logical formula I, c is a number of 1.0～4.

Catalyst the most according to claim 1, it is characterised in that in logical formula I, d is a number of 1.0～4, g be 1～ One number of 20.

Catalyst the most according to claim 1, it is characterised in that in logical formula I, M is lanthanum, mainly comprising by (II) of catalyst Represent: Mo_aV_bW_cCu_dNi_eSn_fSi_gLa_hO_x(II), wherein h is a number of 0.05～2.

7. according to the catalyst described in any one of claim 3～6, it is characterised in that described in mainly comprise and finished catalyst is required for Roasting 3～10h at 350～500 DEG C.

8. the preparation method of catalyst described in claim 1, it is characterised in that include with coprecipitation prepare described in mainly comprise, magnesium Base lanthanum hexaaluminate, by described mainly comprising, magnesio lanthanum hexaaluminate is by 90～98% and 0.1～10% after mass percent mixing Through kneading, molding, it is dried, obtains finished catalyst after roasting.