CN104841446B - Catalyst for selective oxidation of propylene and preparation method of catalyst - Google Patents

Abstract

The invention relates to a multiple-metal-oxide catalyst, which contains molybdenum, bismuth, iron, nickel, cobalt, and tungsten elements. The main compound of the catalyst is represented by general formula (I): Mo<a'>Bi<b'>Fe<c'>Ni<d'>Co<e'>W<f>A<h'>B<i>Si<j>O<y>, and silicon is taken as a carrier, wherein A is at least one element selected from zinc, titanium, and magnesium, and B is at least one element selected from tin, chromium, rubidium, and lanthanum. The catalyst also contains Mg-based lanthanum hexaaluminate. The finished catalyst is obtained by mixing 8-95% by mass percentage of the molybdenum-contained bismuth-contained compound (I) and 0.5-8% by mass percentage of Mg-based lanthanum hexaaluminate, kneading, moulding, drying, and roasting. The catalyst provided in the invention is used for selective oxidation of low-carbon olefin. Active components, such as molybdenum, of the catalyst are not prone to run off, and transformation of active phases is not prone to occur. The catalyst has characteristics of high reaction activity and selectivity and long service life.

Description

Catalyst for Propylene Selectivity oxidation and preparation method thereof

Technical field

The present invention relates to a kind of catalyst of poly-metal deoxide, for being catalyzed propylene Sexual behavior mode oxidation acrolein.

Background technology

Industrial at present main acrylic acid is prepared using propylene two-step oxidizing process, propylene catalytic gas phase oxidation first generates third Olefine aldehydr, acrylic aldehyde is reoxidised into acrylic acid.

The reaction unit that acrylic aldehyde is prepared in industrial propylene oxidation is mainly many reaction tubes, is ensureing that catalyst is not burnt Knot, on the premise of long service life, improve selectivity and purpose product yield as far as possible, save raw material, if feed stock conversion, third Even if olefine aldehydr, acrylic acid yield improve 0.1～0.5 percentage point, the amount of the product obtaining is increased with the level of hundreds of～thousands of tons of Plus, its economic benefit is also very considerable.

It is mainly molybdenum system multicomponent catalyst with regard to propylene fraction oxidation acrolein, acrylic acid catalyst.Due to propylene It is strong exothermal reaction that selective oxidation prepares the acrylic acid reaction of acrylic aldehyde, so be passed through the big water of specific heat in course of reaction steaming Gas, effectively to remove reaction heat, but the easy loss under the washing away of the air-flows such as vapor such as active component molybdenum in catalyst. And, under the high temperature conditions, in catalyst, part active component molybdenum loses because of distillation from catalyst surface.Active component molybdenum Run off and lead to reduce activity, selectivity, intensity and the service life of catalyst, and molybdenum, in the deposition in response system downstream, hinders Plug pipeline affects the long-term operation of system.

In addition, active component molybdenum in catalyst etc. enables keeping not running off, substantially change before and after the reaction of molybdenum equal size Less, but easily there is phase in version through long-term operation activity compatible.Key component in catalyst includes Fe₂(MoO₄)₃、 α-Bi₂(MoO₄)₃、CoMoO₄And NiMoO₄, wherein α-Bi₂(MoO₄)₃It is Active sites, play selective oxidation effect；Fe₂ (MoO₄)₃Play redox facilitation；CoMoO₄And NiMoO₄Play Stability Analysis of Structures effect.However, the coprecipitation method system of adopting Standby catalyst is many due to component, and process is complicated, and catalyst stabilization differs, although initial activity is very high, inactivation is fast.Lead to many Component Mo-Bi-Co-Fe-O catalyst and Mo-V-O catalyst inactivation and stability decline factor have a lot, including because The locally sublimation of Mo component caused by abnormal high temperature (focus) and the change of irreversible crystalline phase etc..These factors all can be drawn Play the change of specificity of catalyst, lead to the service life reducing and shortening catalyst of catalyst activity.By urging to inactivation Agent carries out phenetic analysis, finds Fe₂(MoO₄)₃It is reduced into FeMoO₄, and α-Bi₂(MoO₄)₃It is changed into γ-Bi₂MoO₆.

Solve the above problems, the patent being related to is relatively more, for example, for suppressing the loss of molybdenum, CN1583261 is open a kind of It is selectively oxidized the composition metal of reaction for the gas containing unsaturated aldehyde and a kind of gas of molecule-containing keto in the gas phase Oxide catalyst, its catalyst consists of：[Mo_aV_bCu_cX_d]Y_m[Sb_eZ¹ _fZ² _g]_nO_xWherein Mo is molybdenum, and V is vanadium, and Cu is copper, Sb is antimony, and X is a kind of element being at least selected from tungsten and niobium, and Y is at least to be selected from titanium, a kind of element of antimony, Z₁It is at least chosen from Fe With a kind of element of nickel, Z₂It is at least to be selected from silicon, aluminum, a kind of element of alkali and alkaline earth metal ions, a, b, c, d, e, f, g and x Represent the atomic ratio number of its element, when on the basis of a=12, b is 1 to 6 number, and c is 0.5 to 4 number, and d is 0.05 To 4 number, e is 0.1 to 30 number, and f is 0 to 25 number, and g is 0.01 to 20 number；X is by meeting A number 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, CN1130172 discloses a kind of acrylic acid catalyst, respectively use ammonium metavanadate and Copper nitrate, and replace ammonium metavanadate with low price barium oxide and/or low price Cu oxide part and/or copper nitrate make vanadium metal and Catalyst obtained by the raw material of copper or in addition to above-mentioned raw materials, is obtained using low price sb oxide and/or low price tin-oxide Catalyst show there is a strengthened peak (vanadium-molybdenum reactive compound is peculiar) in d=4.00 and has in d=4.38_ The V of one strength reduction₂O₅Specific peak.So, catalyst obtained above has the catalysis activity of raising, and can be long-term Show stability.Similar also has patent documentation 1：Japanese Unexamined Patent Publication 2002-233757 publication, patent documentation 2：Japan is special Open flat 8-299797 publication, patent documentation 3：Japanese Unexamined Patent Publication 9-194213 publication, patent documentation 4：Japanese Unexamined Patent Application Publication 2004- No. 504288 publications；CN102066000A.

For improving activity, selectivity and the catalyst life of catalyst, the open one kind of CN200980112659.3 comprises The coating catalyst of following components：A () carrier, (b) comprises molybdenum oxide or forms the first of the precursor compound of molybdenum oxide Layer, (c) comprises the second layer of the poly-metal deoxide containing molybdenum and at least one other metal.The molybdenum oxide of preferably ground floor is MoO₃, the poly-metal deoxide that the poly-metal deoxide of the second layer represents for formula II：Mo₁₂Bi_aCr_bX¹ _cFe_dX² _eX³ _fO_y.This is urged Agent is the application type catalyst including carrier.Goal of the invention is suppression heterogeneously catalysed partial gas phase oxidation acrylic aldehyde is propylene The coating catalyst inactivation of acid, has improved inactivation performance.This invention is not expressly recited catalyst and is used for being catalyzed propylene Oxidation acrolein, acrylic acid reactivity worth evaluating data, such as conversion ratio, selectivity, yield etc..CN87103192 is open A kind of method producing composite oxide catalysts, the Mo-Bi composite oxide catalysts wherein being represented with following chemical formula Production method includes formation complex in coherent element source compound incorporation Aquo System and carries out heat treatment to this complex, Using (a) Bi and Na or (b) Bi, Na and X or (c) Bi and X waltherite complex a kind of compound as Bi source, this be combined At least contain in thing partly that required Na and/or X be wherein：X represents 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- 10th, e=0.05-3, f=0.01-1, g=0-1, h=0.04-0.4, i=0-3, j=0-48, k are one and meet other element oxide states Number.Solve Bi can in composite oxide catalysts homodisperse problem.α-Bi is contained in catalyst₂(MoO₄)₃、 MoO₃Fe₂（MoO₄）₃With β-CoMoO₄、_y-Bi₂MoO₆And_γ-Bi₂MoO₆.The open one kind of CN101690900A prepares acrylic aldehyde and third The preparation method of olefin(e) acid catalyst, catalyst supports thing by active component and inert alumina carrier forms；Active component is main Component, selected from Mo, Bi, Co and/or Ni and Fe, also comprises the micro unit such as K, Na, Rb, Cs, Mg, Ca, Zn, B, P, W Element；Wherein active component is represented with following statement formulas：Mo_aBi_bCo_cNi_dFe_eX_fY_gZ_hO_iIn formula, X represents K, Na, Rb and Cs extremely Few one kind, Y represents at least one in B, P and W, and Z represents at least one in Mg, Ca, Zn.Active component supports Ratio on carrier accounts for the 5-70% of overall catalyst weight；Active component is in uneven distribution, CoMoO₄、NiMoO₄Etc. bivalence gold The aluminate belonging to is located at the kernel of catalyst activity component；Fe₂(MoO₄)₃And the MoO of free state₃Invest the outer layer of kernel；And The outermost layer of active component is bismuth molybdate, forms the state of core-shell structure copolymer layer distributed.In active component, bivalence molybdate is mainly β Phase structure, α phase structure content in active component is very low or does not exist.Catalyst has high activity and high stability. A kind of catalyst producing unsaturated aldehyde and unsaturated carboxylic acid of CN1280036, described production is to be selected from by making at least one The compound of propylene, isobutene., the tert-butyl alcohol and methyl tertiary butyl ether(MTBE) and oxygen molecule or the gas containing oxygen molecule carry out vapour phase oxygen Change and realize it is characterised in that this catalyst is a kind of combined oxidation compositions, contain：(A) molybdenum, bismuth and ferrum are contained as master Want the composite oxides of component, itself be known for described vapor phase catalytic oxidation reaction catalyst, and (B) contain cerium and Zirconium is as the composite oxides of key component.Catalyst has long catalytic life and makes to operate steadily in the long term and be possibly realized.Its Middle component (B), is the composite oxides being represented with below general formula (2)：Ce_pZr_qF_rO_y.The zirconium oxide of high degree of dispersion inhibits oxygen Change the gathering of cerium, to keep the latter during the course of the reaction to the promotion functions significantly absorbing and discharging oxygen, thus accelerating different The oxidation reaction of butylene, therefore improves catalysis activity.Additionally, further suppress the component causing because of over reduction in time (A) the irreversible activity of composite oxides reduces (i.e. the stability of composite oxides improves), so that catalytic life is prolonged Long.This catalysis activity that improve and the catalytic life extending inhibit reaction temperature to raise in time, thus reducing Molybdenum is in the distillation of 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 to have The composite oxides of following atomic ratios：Mo: Bi: Co: Ni: Fe=10-14: 1.2-2.0: 4.8-5.6: 2-3: 1-2；This catalyst There is the pore size distribution of more concentration, moderate total pore volume, wherein 5-10nm about mesopore account for more than the 70% of total pore size distribution, shape Become short and thick pore passage structure, this feature gives catalyst stronger anti-carbon deposition ability, catalyst surface not easy-sintering can Extend the service life of catalyst.And the renovation process being provided by the present invention, decaying catalyst carries out in an oxidizing atmosphere 1-3 days calcination processing, catalyst activity is suitable with fresh catalyst.CN87103192 produces Mo-Bi-Na composite oxide catalytic The method of agent product, the method includes mixing coherent element source compound formation complex, then carries out heat treatment, will at least The bismuth subcarbonate of solid solution partly required Na is as Bi source compound.The activity of catalyst imports specific water by means of Bi and Na Insoluble compound formed catalyst and greatly improved.

CN1109803 is related to multimetal oxide compositions, and they have two phase structure and comprise molybdenum, hydrogen, one or many Individual element phosphor, arsenic, boron, germanium and silicon；And it is related to described compositionss in terms of methacrylic acid is prepared by catalytic gas phase oxidation Purposes, improves activity and selectivity.CN1109802 discloses a kind of multimetal oxide compositions, and they have two phase structure simultaneously 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 using the composite oxides adding magnesium, aluminum and silicon.CN1321110A is then respectively with stibium oxide and antimony acetate Antimony source as active metal composite oxide.To solve under high-load condition, catalytic mechanical intensity is good, active high asking Topic.CN200410048021.7 discloses a kind of O composite metallic oxide catalyst, and catalyst is by 1. molybdenum, vanadium, copper chief active Component and 2. requisite at least by antimony and titanium stable component and 3. nickel, ferrum, silicon, aluminum, alkali metal, alkaline-earth metal form Composite oxides.2. and be 3. wherein can in the range of 120 DEG C to 900 DEG C roasting preparation composite oxides.This catalyst Show the permanent stability under high activity and good selectivity.The open one kind of CN1121441 is used for by acrylic aldehyde or contains third Olefine aldehydr gas and a kind of gas of molecule-containing keto carry out oxidation reaction in vapour phase and produce acrylic acid catalyst, this catalyst bag Include a kind of (A) composite oxides, there is molybdenum and vanadium as base stock, and be suitable to produce by vapor phase catalytic oxidation acrylic aldehyde Acrylic acid, and a kind of (B) solid peracid, its acid strength (Ho) is not more than -11.93 (Ho≤- 11.93).This invention adopts molybdenum vanadium type The solid acid that composite oxides are less than -11.93 with a kind of acid strength combines, and improves the low temperature high activity of catalyst. CN200510059468.9 discloses a kind of acrylic acid catalyst for producing, it is characterized in that, in following formula M oaVbWcCudOx (1) The oxide of metallic element composition representing and/or the acrylic acid catalyst for producing that composite oxides are necessary catalyst component In, need the face side controlling tungsten to be partially 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 is that the core side of this catalyst is difficult to accurately control partially. CN102039143A discloses the preparation method that a kind of acrolein oxidation prepares acrylic acid catalyst, a) composite oxide coating Preparation method：Water-soluble metal salt containing Mo, V, W, Cu, Sb composition is dispersed in water/organic faciess mixing in 30-100 DEG C In system；Organic solvent and water weight ratio is kept to be 5～50%；Reaction generates composite oxides presoma serosity；Again through steaming Evaporate, dry, roasting is obtained catalyst activity component；B) the main component of above-mentioned active component, selected from Mo, V, Cu, W, Sb its In one or more；Wherein active component following formula represents：Mo_aV_bCu_cW_dSb_eO_f, this catalyst adopts water and lower alcohol Prepared by mixed system, catalyst has higher specific surface area and special microstructure, has compared with high-ratio surface and is difficult Come off, and bearing capacity can reach 50% and more than, solve the problems, such as that application type catalyst service life is shorter.

CN1647854 discloses a kind of acrylic acid catalyst of methylacrolein selective oxidation synthesizing methyl, this catalyst Forming formula is：x(Mo₁₂P_aK_bSb_cCu_dAs_eA_fD_gQ_hO_iMo_j)/yZ, Z dilute thermal conducting agent for carrier；Mo, P, K, Sb, Cu and As It is respectively molybdenum, phosphorus, potassium, antimony, copper and arsenic；A represents at least one of tungsten W, vanadium V, niobium Nb, ferrum Fe and lead Pb element；D represent boron, At least one of gallium Ga, indium In, germanium Ge and silicon Si element；Q represents at least one of rubidium Rb, caesium Cs and thallium Tl element, this invention On the one hand improve the activity and selectivity of catalyst by adding Sb, Cu and As；On the other hand pass through to add MoO₃And carrier Heat conduction diluent improving heat stability, heat conductivility and the mechanical strength of catalyst, inhibitory activity component heteropoly acid effectively The decomposition of salt and reduction beds hot(test)-spot temperature, it is to avoid the loss of Mo and As, extend catalyst service life.

CN1109800 discloses a kind of polymetal oxide materials：In formula, A is Mo₁₂V_aX_b ¹X_c ²X_d ³X_e ⁴X_f ⁵X_g ⁶O_x(coexist Phase), its part B comprises the crystallite with the X-ray diffraction pattern of at least one following copper molybdate（Give in round parentheses Close the raw data of X-ray diffraction fingerprint）：Cu₃(MoO₄)₂(OH)₂（Lindgrenite, JCPDS-ICDD indexes（1991）Index card Piece 36-405）, Cu₄Mo₆O₂₀（A.Moini et al., Inorg.Chem.25（21）（1986）, 3782-3785）, Cu₄Mo₅O₁₇ （JCPDS-ICDD indexes（1991）Index card 39-181）, etc..CN1462211 be related to one kind prepare containing Mo, V, Cu and The method of the optional multiple-phase multi-metal oxide materials of other elements.According to this invention, at least one mutually independently shape in advance Become, and in the precursor material of the plastically deformable being dispersed in another phase.Then this mixture is dried and calcines.Multi-metal oxygen Compound material is suitable as in catalytic gas phase oxidation organic compound, particularly acrolein oxidation is being become used in acrylic acid The active material of catalyst.[A] p [B] q [C] r (I), phase A, B in multimetal oxide compositions and C can be unbodied And/or crystallization.Phase B is advantageously made up of the crystallite of oxometallate, or comprises with X-ray diffraction pattern and enter And the crystal structure class α-CuMo of the oxometallate crystallite copper molybdate of crystal structure types of at least one following copper molybdate₄ [the registration card 22-242 of JCPDS-ICDD card index, (1991)], Cu₆Mo₅O₁₈[the registration card of JCPCS-ICDD card index 40-865, (1991)], Cu_4-xMo₃O₁₂, wherein x=0-0.25 [registration card 24-56 and 26- of JCPCS-ICDD card index 547, (1991)], etc..This catalyst is to improve selectivity.

CN1295499 discloses a kind of polymetal oxide materials [A] p [B] q [C] r (I) of formula (I), with containing molybdenum, vanadium, Copper and antimony and one or more specific other metal simultaneously have the polymetal oxide materials of multicomponent structure as with propylene The gas phase catalytic oxidation reaction of aldehyde prepares acrylic acid catalyst.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 contain such copper molybdate crystallite：α-CuMoO₄[the reference diffraction in the index card 22-242 of JCPDS-ICDD retrieval 1991 Figure], Cu₆Mo₅O₁₈[reference diffraction pattern in the index card 40-865 of JCPDS-ICDD retrieval 1991], Cu_4-xMo₃O₁₂Wherein, x For 0-0.25 [JCPDS-ICDD retrieval 1991 index card 24-56 and 26-547 in reference diffraction pattern], etc..Region C is permissible There is metaantimmonic acid copper Cu₉Sb₄O₁₉The crystallite of structure or Cu₄SbO₄.₅The crystallite of structure.CN1093950 discloses one kind of multiple metal oxygens The compositionss of compound, including Mo, V, W, Cu, Ni of the oxidised form as basis, its premise is to become to divide it in each element Between there is following ratio：Mo:V=12:1 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；X₄Be Sb and/or Bi；X₅It is Si, Al, Ti and/or Zr.CN1387945 is related to containing in Cu, Mo and at least one W, V, Nb and Ta selected from element The oxo metal compound of the HT copper molybdate structure type of element, its preparation method, and they are in preparation containing molybdenum, vanadium, copper simultaneously Containing answering in the composite metal oxide material having heterogeneous structure of one or more element in elemental tungsten, niobium, tantalum, chromium and cerium With.CN1394812 poly-metal deoxide, institute used in the catalyst for the catalytic vapor phase oxidation reaction of organic compound The poly-metal deoxide said contains at least one in Mo, V and element W, Nb, Ti, Zr, Hf, Ta, Cr, Si and Ge, and has spy Different Three-dimensional atom arrangement.CN1500770 contains molybdenum, vanadium, copper and contains one or more yuan in elemental tungsten, niobium, tantalum, chromium and cerium The composite metal oxide material having heterogeneous structure of element, they are by answering in catalytic gas phase oxidation of acrolein acrylic acid With, and the oxo of the HT copper molybdate structure type containing the element in Cu, Mo and at least one W, V, Nb and Ta selected from element Metal compound.

In addition, under the high temperature conditions, in catalyst, part active component molybdenum loses because of distillation from catalyst surface.Propylene Aldehyde, air（Oxygen）, the mixed airflow such as nitrogen and vapor wash away the loss of active component that also can make in catalyst.For suppression The loss of molybdenum distillation causes the decay of activity, and CN1121504 passes through to mix copper component and has specified particle diameter and specific surface area Zirconium and/or titanium and/or cerium, can suppress dissipation effect and the over reduction of molybdenum composition.Catalyst is included by lower formula (I) MO_aV_bW_cCu_dX_eY_f(I) oxide of metallic element composition representing or composite oxides.CN1445020 adds a small amount of tellurium to play Stable free molybdenum trioxide and the effect of copper molybdate crystal structure, the sublimation of molybdenum and over reduction have suppressed； Composite oxides or its oxide with molybdenum, vanadium, copper, tungsten and/or niobium as key component, with other elements composition for the CN1583261 Mixture form catalyst suppress molybdenum loss.

Accordingly, it is desirable to provide acrylic aldehyde, acrylic acid catalyst, catalyst activity component molybdenum etc. are prepared in Propylene Selectivity oxidation Not easily run off, and activity is mutually not susceptible to phase in version, stably selective oxidation produces acrylic aldehyde propylene to make propylene long period Acid, improves selectivity and the yield of purpose product, as far as possible to obtain bigger economic benefit.

Content of the invention

It is an object of the invention to provide a kind of Propylene Selectivity oxidation produces acrylic aldehyde, acrylic acid poly-metal deoxide is urged Agent and preparation method thereof.

The present invention relates to a kind of be used for Propylene Selectivity oxidation catalyst, catalyst contains molybdenum, bismuth, ferrum, nickel, cobalt and tungsten unit Element, mainly forms by formula M o_a′Bi_b′Fe_c′Ni_d′Co_e′W_fA_h′B_iSi_jO_y（Ⅰ）Represent, wherein：Mo is molybdenum, and Bi is bismuth, and Fe is Ferrum, Co is cobalt, and Ni is nickel, and W is tungsten, and Si is silicon, silicon be in catalyst add carrier, A be in zinc, titanium, potassium at least A kind of element；B is at least one element in stannum, chromium, rubidium, lanthanum；O is oxygen；A ', b ', c ', d ', e ', f, h ', i, j are respectively Represent each element atomic ratio, wherein a ' is a number of 12-14, and b ' is a number of 0.5-6, preferably 1.0-5；C ' is 0.2-4 A number, preferably 0.2-3；D ' is a number of 0.2-5, preferably 0.5-4；E ' is a number of 0.2-5, preferably 0.5-4, f It is a number of 0.1-3.5, h ' is a number of 0.1-5, i is a number of 0.1-3.5, j is a number of 0.5-30, y is The numerical value being determined by the oxygen of each oxide.Catalyst also contains magnesio lanthanum hexaaluminate, containing molybdenum, bismuth（Ⅰ）With magnesio lanthanum hexaaluminate （LaMgAl₁₁O₁₉）Become after kneading, molding, drying, roasting after mixing with 1～10% mass percent by 90～98% Product catalyst.

Formula of the present invention（Ⅰ）In be preferably added to active component lanthanum, lanthanum and bismuth, cobalt, stannum can form stable crystal phase structure, such as BiLa、BiLa₂、Co₃La₂、LaNi₅, LaSn etc., the good dispersion of molybdenum, thus suppress part active component molybdenum from catalyst surface Lose because of distillation, active component molybdenum not easily runs off, before and after catalyst reaction, active component molybdenum content is basically unchanged, and delays activity Deterioration rate, catalyst activity and good stability.Lanthanum and molybdenum, cobalt ratio are suitable, formula（Ⅰ）Middle B is lanthanum, and i is 0.1～3.5 One number, the addition of excessive lanthanum can compete molybdenum with bismuth, cobalt and ferrum, affects catalyst activity.The preferred sodium stannate of Xi Yuan of the present invention, chlorine Change stannous.Main composition by（Ⅱ）Represent：Mo_a′Bi_b′Fe_c′Ni_d′Co_e′W_fA_hB_iSi_jO_y（Ⅱ）.

It is highly preferred that catalyst can be contained in catalyst of the present invention（Ⅰ）91～96%, containing magnesio lanthanum hexaaluminate 1.5～6%.

Under Oxygen Condition, molybdenum isoreactivity component is not only easy to run off catalyst under the high temperature conditions, and activity compatible is easy There is phase in version, activity mutually occurs phase in version thus leading to active selectable to be decreased obviously.As such as active phase CoMoO₄It is converted into Co₃O₄, Fe₂(MoO₄)₃It is transformed into FeMoO₄, α-Bi₂(MoO₄)₃It is changed into γ-Bi₂MoO₆Deng.

Active component molybdenum in catalyst etc. enables holding and does not run off, and before and after the reaction of molybdenum equal size, basic change is little, But easily there is phase in version through long-term operation activity compatible.The present invention adds lanthanum-magnesium aluminate oxide in catalyst, makes Catalyst activity is mutually more stable, is not susceptible to phase in version thus improving catalyst activity and selectivity.

Magnesio lanthanum hexaaluminate oxide of the present invention is prepared according to conventional coprecipitation.As using the preparation of following methods：Will Magnesium nitrate, Lanthanum (III) nitrate and aluminium hydroxide are according to LaMgAl₁₁O₁₉Stoichiometric proportion mix homogeneously, add deionized water simultaneously to stir Uniformly, be then spray-dried, gained powder after 160 DEG C of dryings through 1000～1500 DEG C of roastings 3～12 hours, then by pulverize Or the method such as ball milling obtains magnesio lanthanum hexaaluminate LaMgAl below 20 μm for the particle diameter₁₁O₁₉.

The multi-metal-oxide catalyst of the present invention（Ⅰ）Using common preparation method, such as following steps can be adopted Rapid preparation, by A in the compound containing Mo, Bi, Fe, Fe, Co, W and logical formula I_hB_iThe each element component composition that part is related to In proportion dissolving and mix homogeneously, after being co-precipitated formed serosity, in slurry production process add silicon dioxide, aluminium oxide or One or more of carborundum, dries, molding, roasting obtains catalyst（Ⅰ）Powder.

The preparation method of catalyst of the present invention, prepares catalyst (I), magnesio lanthanum hexaaluminate including with coprecipitation, will urge Agent (I), magnesio lanthanum hexaaluminate are pressed after 90～98% and 1～10% mass percent mixes through kneading, molding, drying, roasting Deng after obtain finished catalyst.

Catalyst of the present invention（Ⅰ）Powder and finished catalyst are required for roasting 3～10h at 400～580 DEG C, compare Do not distinguish the catalyst of roasting, multiple roasting can improve activity and the stability of catalyst.Can be that open roasting can also It is enclosed roasting, calcination atmosphere can be the noble gases such as helium, nitrogen, argon.

Catalyst Formula of the present invention（Ⅰ）In each component compound can use the nitrate of each element, ammonium salt, Sulfate, oxide, hydroxide, chloride, acetate etc., such as Lanthanum (III) nitrate, magnesium nitrate, ammonium chromate, rubidium nitrate, zinc nitrate, Titanium dioxide, sodium stannate etc..

It is usually preferred to adopt the molding side such as extrusion molding, granulating and forming, compression molding after catalyst slurry of the present invention is dried Method processing glomeration, hollow spheres, ellipticity, cylindric, hollow circuit cylinder etc., preferably hollow circuit cylinder or spherical.

The present invention, in order to improve intensity, the efflorescence degree of catalyst, can add glass fibre, stone in above-mentioned catalyst One or more in black, ceramic or various whisker.

Catalyst activity of the present invention is high, suitable Propylene Selectivity oxidation acrolein, acrylic acid.

Evaluating catalyst performance index definition is as follows：

Specific embodiment

With specific embodiment, multi-metal-oxide catalyst and preparation method thereof is described below, and this catalyst is in propylene Selective oxidation prepares the catalytic performance of acrylic aldehyde, but the scope of the present invention is not limited to these embodiments.Following examples are adopted Propylene is propylene content >=99.6%（Volume fraction）High concentration propylene.The analysis method of product form adopts this area Universal method.

Embodiment 1

The preparation of catalyst 1

Under agitation, 217.5 grams of ammonium molybdates are taken to be dissolved in 1000ml pure water（More than 65 DEG C of water temperature）, starched Liquid（1）, then take 56.3 grams of cobalt nitrates, 43.5 grams of nickel nitrates, 88.9 grams of ferric nitrates, 23 grams of ammonium paratungstates, 42.9 grams of Lanthanum (III) nitrates It is dissolved in 500ml pure water（More than 65 DEG C of water temperature）, it is thoroughly mixed uniformly, obtain serosity（2）.Take 170.8 grams of nitric acid again Bismuth, is dissolved under agitation in dust technology, obtains serosity（3）.Then, serosity（1）With serosity（2）Mixing, obtains serosity （4）, then by serosity（3）Add serosity（4）In, obtain active component serosity（a）.

Active component serosity (a) and 7.9 grams of silicon dioxide powders are carried out coprecipitation reaction post-heating drying, in nitrogen with 150 DEG C of heat treatments 3 hours, then 500 DEG C of roastings 4 hours, size-reduced, grind, sieving processes to obtain catalyst（Ⅰ）Powder, mainly Consist of：Mo₁₄Bi₄Fe_2.5Ni_1.7Co_2.2W_1.0La_1.5Si_1.5O_y（Ⅰ）.

By magnesium nitrate, Lanthanum (III) nitrate and aluminium hydroxide according to LaMgAl₁₁O₁₉Stoichiometric proportion mix homogeneously, add depart from Sub- water simultaneously stirs, and is then spray-dried, gained powder after 160 DEG C of dryings through 1100 DEG C of roastings 10 hours, then pass through ball The methods such as mill obtain magnesio lanthanum hexaaluminate LaMgAl below 20 μm for the particle diameter₁₁O₁₉.

Take catalyst（Ⅰ）95 parts, 5 parts of magnesio lanthanum hexaaluminate, plus deionized water mediates in kneader, extrusion molding is φ The hollow columnar granule of 4.5 × 5mm, is dried under the conditions of 120 DEG C, and roasting at 500 DEG C obtains catalyst 1 in 3.5 hours.

Embodiment 2

The preparation of catalyst 2

Preparation process and primary raw material with embodiment 1 catalyst 1 are identical, obtain final product catalyst within 3 hours through 550 DEG C of roastings （Ⅰ）.Catalyst（Ⅰ）Mainly consist of：

Mo₁₄Bi_1.2Fe_1.2Ni_4.5Co_3.1W_0.3Zn_1.1Ti_1.2Sn_0.3Si_3.1O_y（Ⅰ）

Take catalyst（Ⅰ）91 parts, 9 parts of magnesio lanthanum hexaaluminate, plus deionized water mediates in kneader, extrusion molding is φ The hollow columnar granule of 4.5 × 5mm, is dried under the conditions of 120 DEG C, and roasting at 500 DEG C obtains catalyst 2 in 3.5 hours.

Embodiment 3

Preparation process and primary raw material with embodiment 1 catalyst 1 are identical, obtain final product catalyst within 8 hours through 400 DEG C of roastings （Ⅰ）.Mainly consist of：Mo₁₄Bi₆Fe₃Ni_0.6Co_1.6W₃Zn_1.5Cr_0.1Rb_0.2Si_4.1O_y（Ⅰ）.Take catalyst（Ⅰ）97 parts, magnesio six 3 parts of lanthanum aluminate, plus deionized water mediates in kneader, extrusion molding is the hollow columnar granule of φ 4.5 × 5mm, 120 DEG C of bars It is dried under part, roasting at 500 DEG C obtains catalyst 3 in 4 hours.

Embodiment 4

Preparation process and primary raw material with embodiment 1 catalyst 1 are identical, obtain final product catalyst within 5 hours through 550 DEG C of roastings （Ⅰ）.Mainly consist of：Mo₁₃Bi_4.6Fe_1.7Ni_3.3Co₅W₂La_0.8Sn_0.5Si_2.7O_y（Ⅰ）, take catalyst（Ⅰ）93 parts, magnesio six aluminum 7 parts of sour lanthanum, plus deionized water mediates in kneader, extrusion molding is the hollow columnar granule of φ 4.5 × 5mm, 120 DEG C of conditions Lower drying, roasting at 500 DEG C obtains catalyst 4 in 4 hours.

Comparative example 1

According to the main composition and ratio preparation comparative catalyst 1 of embodiment 1, but magnesio lanthanum hexaaluminate is not with solid solution The form of oxide adds catalyst, but prepares catalyst with coprecipitation method, and reaction condition is with the evaluation bar of catalyst 1 Part.Comparative catalyst 1 mainly consists of：

Mo₁₄Bi₄Fe_2.5Ni_1.7Co_2.2W_1.0La_1.8Si_1.5Mg_0.3Al_3.3O_y

Oxidation reaction

Fixed bed single tube reactor internal diameter 25mm, inside sets thermocouple, loads 50ml along propylene feed orienting response device bed Above-mentioned catalyst or comparative example catalyst, 307 DEG C of salt bath heating temperature.Tube inlet sentences air speed 1400h from the reactions above^-1Import Propylene 10 volume %, air 72 volume %, the mixed gas of vapor 18 volume %.Reaction result is as shown in table 1.React 24 little When load not higher than 358 DEG C of beds hot localised points temperature of the present invention, reaction bed temperature indexing is more reasonable, improves Purpose product selectivity and yield, acrylic aldehyde and acrylic acid total recovery more than 91.0%, the catalyst reaction of embodiment 1 and 4 After 2000h, bed hot localised points temperature is respectively 358 DEG C, 356 DEG C, and propylene conversion is respectively 99.1% and 98.7%, acrylic aldehyde （ACR）Selectivity respectively 88.7% and 88.5%, acrylic aldehyde yield 81.2 and 80.8, acrolein+acrylic acid yield 91.5%, 91.3%.In the case of vapor intake 18 volume %, through the reaction of 2000 hours, catalyst activity component molybdenum etc. was no It is easy to run off, and activity is mutually not susceptible to phase in version, during acrolein oxidation, reaction bed temperature is distributed more adduction Reason.Acrylic aldehyde（ACR）And acrylic acid（AA）Total recovery more than 91.0%, catalyst activity component Stability Analysis of Structures, catalyst has good Good water repelling property, catalyst performance stabilised.Comparative example catalyst choice is poor, and acrylic aldehyde, acrylic acid yield are low.

Table 1 reacts 24 hours post-evaluation results

Claims (10)

1. a kind of catalyst for Propylene Selectivity oxidation is it is characterised in that catalyst contains molybdenum, bismuth, ferrum, nickel, cobalt and tungsten unit Element, mainly forms by formula M o_a′Bi_b′Fe_c′Ni_d′Co_e′W_fA_h′B_iSi_jO_y(I) represent, wherein silicon is carrier, A be selected from zinc, At least one element in titanium, potassium；B is at least one element in stannum, chromium, rubidium, lanthanum；O is oxygen；a′、b′、c′、d′、 E ', f, h ', i, j represent each element atomic ratio respectively, and wherein a ' is a number of 12-14, and b ' is a number of 0.5-6, and c ' is One number of 0.2-4, d ' is a number of 0.2-5, and e ' is a number of 0.2-5, and f is a number of 0.1-3.5, and h ' is 0.1- 5 number, i is a number of 0.1-3.5, and j is a number of 0.5-30, and y is the numerical value being determined by the oxygen of each oxide；Urge Agent also contains magnesio lanthanum hexaaluminate, presses 90～98% and 1～10% percent mass containing molybdenum, (I) of bismuth and magnesio lanthanum hexaaluminate Obtain finished catalyst than after mixing after kneading, molding, drying, roasting.

2. catalyst according to claim 1 is it is characterised in that contain catalyst (I) 91～96%, containing magnesio six aluminum Sour lanthanum 1.5～6%.

3. catalyst according to claim 1 it is characterised in that in catalyst (I) b ' be a number of 1-5.

4. catalyst according to claim 1 it is characterised in that in catalyst (I) c ' be a number of 0.2-3.

5. catalyst according to claim 1 it is characterised in that in catalyst (I) d ' be a number of 0.5-4.

6. catalyst according to claim 1 it is characterised in that in catalyst (I) e ' be a number of 0.5-4.

7. catalyst according to claim 1 it is characterised in that in catalyst (I) B be lanthanum, i is of 0.1～3.5 Number.

8. according to any one of claim 1～7 catalyst it is characterised in that the preparation of catalyst (I) comprises the steps： 1) Mo, Bi, A in the compound of Fe, Ni, Co, W and logical formula I will be contained_hB_iThe each element component composition that is related to dissolve simultaneously Mix homogeneously, forms serosity after being co-precipitated, and adds one of silicon dioxide or carborundum or many in slurry production process Kind, dry, molding, roasting obtains catalyst (I) powder.

9. according to claim 1 the preparation method of catalyst it is characterised in that including preparing catalyst with coprecipitation (I), magnesio lanthanum hexaaluminate, catalyst (I), magnesio lanthanum hexaaluminate are pressed after 90～98% and 1～10% mass percent mixing Obtain finished catalyst after kneading, molding, drying, roasting.

10. preparation method according to claim 9 is it is characterised in that roast after catalyst (I) molding at 400～580 DEG C Burn 3～10h.