| abstract |
Provided is a catalyst that can produce methacrylic acid at high selectivities by the gas-phase catalytic oxidation of methacrolein. The catalyst is a catalyst for production of methacrylic acid which is used for the production of methacrylic acid by the gas-phase catalytic oxidation of methacrolein using molecular oxygen and has the following composition.nP a Mo b V c Nb d Cu e A f E g G h (NH 4 ) i O j n(A represents at least one of Si, Ge, As, and Sb; E represents at least one of Bi, Zr, Te, Ag, Se, W, B, Fe, Zn, Cr, Mg, Ca, Sr, Ta, Co, Ni, Mn, Ba, Ti, Sn, Pb, In, S, Pd, Ga, Ce, and La; and G represents at least one of Li, Na, K, Rb, Cs, and Tl. The following are satisfied for b = 12: 0.5 ≤ a + f ≤ 2.1, 0.01 ≤ c + d ≤ 3, 0.5 ≤ a, 0 ≤ c, 0.01 ≤ d ≤ 3, 0.005 ≤ e ≤ 3, 0 ≤ f, 0 ≤ g ≤ 3, 0.01 ≤ h ≤ 3, and 0 ≤ i ≤ 5, and j is the molar ratio for oxygen that satisfies the valences of the individual components.) |