Method for producing catalyst and method for producing acrylonitrile

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.