Abstract: An oxide catalyst for use in an oxidation reaction of an olefin and/or an alcohol, the oxide catalyst comprising: the oxide catalyst contains molybdenum, bismuth, iron, cobalt, and cerium; an atomic ratio a of bismuth to 12 atoms of molybdenum is 2?a?6, an atomic ratio b of iron to 12 atoms of molybdenum is 2.5<b?5, an atomic ratio c of cobalt to 12 atoms of molybdenum is 2?c?8, an atomic ratio d of cerium to 12 atoms of molybdenum is 0.5?d?6, and an atomic ratio of iron/cobalt is 0.4?b/c?2.5; wherein when a spacing d of a complex oxide of cerium and molybdenum showing a peak at 33.50° in a X-ray diffraction is taken as a reference, a change rate of d is 5000 to 9000 ppm.

Abstract: An oxide catalyst for use in an oxidation reaction of an olefin and/or an alcohol, the oxide catalyst comprising: the oxide catalyst contains molybdenum, bismuth, iron, cobalt, and cerium; an atomic ratio a of bismuth to 12 atoms of molybdenum is 2?a?6, an atomic ratio b of iron to 12 atoms of molybdenum is 2.5<b?5, an atomic ratio c of cobalt to 12 atoms of molybdenum is 2?c?8, an atomic ratio d of cerium to 12 atoms of molybdenum is 0.5?d?6, and an atomic ratio of iron/cobalt is 0.4?b/c?2.5; wherein when a spacing d of a complex oxide of cerium and molybdenum showing a peak at 33.50° in a X-ray diffraction is taken as a reference, a change rate of d is 5000 to 9000 ppm.