# US 2019/0168191 A1 · Method for producing catalyst and method for producing acrylonitrile > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0168191 A1 - Document ID: US20190168191A1 - Status: Published application - Kind: A1 - Application number: 16/320,428 - Filed: 2017-08-01 - Published: 2019-06-06 - Earliest claimed: 2016-08-31 - Assignees: Asahi Kasei Kabushiki Kaisha - Applicants: Asahi Kasei Kabushiki Kaisha - Inventors: Shota AIKI; Akiyoshi FUKUZAWA - Web page: https://patentgrep.com/patent/US20190168191A1 ## CPC - B01J 23/8878: {Chromium} - B01J 21/08: Silica - B01J 23/002: {Mixed oxides other than spinels, e.g. perovskite} - B01J 23/8876: {Arsenic, antimony or bismuth} - B01J 35/394: {Metal dispersion value, e.g. percentage or fraction} - B01J 35/396: {Distribution of the active metal ingredient} - B01J 35/40: characterised by dimensions, e.g. grain size (in a colloidal state B01J35/23; crystallite size B01J35/77) - B01J 35/51: Spheres - B01J 37/0045: {Drying a slurry, e.g. spray drying} - B01J 37/04: Mixing {(B01J37/0009, B01J37/0018 take precedence)} - B01J 37/088: {Decomposition of a metal salt} - C07C 253/18: by reaction of ammonia or amines with compounds containing carbon-to-carbon multiple bonds other than in six-membered aromatic rings - B01J 2235/00: Indexing scheme associated with group B01J35/00, related to the analysis techniques used to determine the catalysts form or properties - B01J 2235/30: Scanning electron microscopy; Transmission electron microscopy - B01J 2523/00: Constitutive chemical elements of heterogeneous catalysts - Y02P 20/52: using catalysts, e.g. selective catalysts - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract A method for producing a catalyst according to the present invention includes: a preparation step of preparing a precursor slurry comprising molybdenum, bismuth, iron, silica, and a carboxylic acid; a drying step of spray-drying the precursor slurry and thereby obtaining a dried particle; and a calcination step of calcining the dried particle, wherein the preparation step comprises: a step (I) of mixing a starting material for silica with the carboxylic acid and thereby preparing a silica-carboxylic acid mixed liquid; and a step (II) of mixing the silica-carboxylic acid mixed liquid, molybdenum, bismuth, and iron. ## Claims ### Claim 1 A method for producing a catalyst, comprising: a preparation step of preparing a precursor slurry comprising molybdenum, bismuth, iron, silica, and a carboxylic acid; a drying step of spray-drying the precursor slurry and thereby obtaining a dried particle; and a calcination step of calcining the dried particle, wherein the preparation step comprises: a step (I) of mixing a starting material for silica with the carboxylic acid and thereby preparing a silica-carboxylic acid mixed liquid; and a step (II) of mixing the silica-carboxylic acid mixed liquid, molybdenum, bismuth, and iron. ### Claim 2 (depends on 1) The method for producing the catalyst according to claim 1, wherein the catalyst comprises: a metal oxide having a bulk composition represented by the following formula (1); and silica: Mo12BiaFebXcYdZeOf (1) wherein X represents at least one element selected from the group consisting of nickel, cobalt, magnesium, calcium, zinc, strontium, and barium; Y represents at least one element selected from the group consisting of cerium, chromium, lanthanum, neodymium, yttrium, praseodymium, samarium, aluminum, gallium, and indium; Z represents at least one element selected from the group consisting of potassium, rubidium, and cesium; a, b, c, d, e and f represent an atomic ratio of each element, and satisfy 0.1≤a≤3.0, 0.1≤b≤3.0, 0.1≤c≤10.0, 0.1≤d≤3.0, and 0.01≤e≤2.0, respectively, and f represents a number of oxygen atoms needed to satisfy atomic valence requirements of the other elements present therein. ### Claim 3 (depends on 2) The method for producing the catalyst according to claim 2, wherein in the catalyst, a standard deviation of values obtained by dividing a ratio of a molar concentration of Bi to a molar concentration of Mo on a surface of catalyst particles by a ratio of a molar concentration of Bi to a molar concentration of Mo in a metal oxide bulk is 0.2 or less. ### Claim 4 (depends on 1) The method for producing the catalyst according to claim 1, wherein the step (II) comprises the following (i) step and (ii) step, and the drying step comprises the following (iii) step; (i) a step of preparing a Mo-containing liquid comprising at least Mo and a Bi-containing liquid comprising at least Bi, (ii) a step of continuously supplying the Mo-containing liquid to a first flow channel, continuously supplying the Bi-containing liquid to a second flow channel, and merging the first flow channel and the second flow channel at downstream from both points of supply of the Mo-containing liquid and the Bi-containing liquid, and consequently mixing the Mo-containing liquid and the Bi-containing liquid to thereby obtain a MoBi-containing liquid, and (iii) a step of drying the MoBi-containing liquid. ### Claim 5 (depends on 4) The method for producing the catalyst according to claim 4, further comprising (iv) a step of further mixing the MoBi-containing liquid performed between the (ii) step and the (iii) step. ### Claim 6 (depends on 4) The method for producing the catalyst according to claim 4, further comprising (v) a step of storing the MoBi-containing liquid performed between the (ii) step and the (iii) step. ### Claim 7 (depends on 6) The method for producing the catalyst according to claim 6, wherein a series of treatments of the (i), (ii), and (v) steps is performed in a batch treatment methodology, and a whole amount of one batch of the MoBi-containing liquid obtained in the (ii) step is stored in the (v) step: and in the (ii) step, when mass supply rates of the Mo-containing liquid and the Bi-containing liquid to the first flow channel and the second flow channel, respectively, are denoted as mA (g/min) and mB (g/min), respectively, 60% by mass or more of a total amount of whole amounts of the Mo-containing liquid and the Bi-containing liquid supplied per batch, MA (g) and MB (g), respectively, is supplied such that the following formula (2) is satisfied: (mB/mA)/(MB/MA)=0.5 to 1.5 (2). ### Claim 8 (depends on 4) The method for producing the catalyst according to claim 4, wherein the MoBi-containing liquid is continuously supplied to the (iii) step. ### Claim 9 (depends on 4) The method for producing the catalyst according to claim 4, wherein in the (ii) step, when molar supply rates of the Mo-containing liquid and the Bi-containing liquid to the first flow channel and the second flow channel, respectively, are denoted as mα (mol/min) and mβ (mol/min), respectively, the Mo-containing liquid and the Bi-containing liquid are supplied such that the following formula (3) is satisfied: (mβ/mα)/(a/12)=0.8 to 1.2 (3). ### Claim 10 (depends on 1) A method for producing acrylonitrile, comprising: a step of obtaining the catalyst by the method for producing the catalyst according to claim 1; and a step of reacting propylene, molecular oxygen, and ammonia in a presence of the catalyst. ### Claim 11 A catalyst comprising a particle, the particle comprising: a metal oxide having a bulk composition represented by the following formula (1); and silica, wherein a standard deviation of values obtained by dividing a ratio of a molar concentration of Bi to a molar concentration of Mo on a surface of the catalyst particles by a ratio of a molar concentration of Bi to a molar concentration of Mo in a metal oxide bulk is 0.2 or less: Mo12BiaFebXcYdZeOf (1) wherein X represents at least one element selected from the group consisting of nickel, cobalt, magnesium, calcium, zinc, strontium, and barium; Y represents at least one element selected from the group consisting of cerium, chromium, lanthanum, neodymium, yttrium, praseodymium, samarium, aluminum, gallium, and indium; Z represents at least one element selected from the group consisting of potassium, rubidium, and cesium; a, b, c, d, e and f represent an atomic ratio of each element, and satisfy 0.1≤a≤3.0, 0.1≤b≤3.0, 0.1≤c≤10.0, 0.1≤d≤3.0, and 0.01≤e≤2,0, respectively, and f represents a value satisfying a balance of atomic valences. ### Claim 12 (depends on 11) A method for producing acrylonitrile, comprising a step of reacting propylene, molecular oxygen, and ammonia in a presence of the catalyst according to claim 11.