Catalyst for oxidation or ammoxidation

A catalyst for use in catalytic oxidation or ammoxidation of propane or isobutane in the gaseous phase, which comprises an oxide represented by the following formula (1):

• Mo1VaNbbSbcOn (1)
• wherein:
• a, b, c and n are, respectively, the atomic ratios of vanadium (V), niobium (Nb), antimony (Sb) and oxygen (O), relative to molybdenum (Mo),
• wherein:
• 0.1≦a≦1,
• 0.01≦b≦1,
• 0.01≦c≦1, and
• n is the number of oxygen atoms required to satisfy the valence requirements of the other component elements present,
• said catalyst having a reduction ratio of from 8 to 12% and a specific surface area of from 5 to 30 m2/g,
• said reduction ratio being represented by the following formula (2):
• reduction ratio (%)=((n0−n)/n0)×100 (2)
• wherein:
• n is as defined for formula (1), and
• n0 is the number of oxygen atoms required when the other component elements in said oxide of formula (1) respectively exhibit the maximum oxidation numbers of the other component elements.