A process for preparing saturated carboxylic acids having from one to four carbon
atoms by gas-phase oxidation, includes reacting 2-butanone with oxygen over a coated
catalyst which is an inert nonporous support body and a catalytically active mixed
oxide composition comprising (a) one or more oxides selected from the group consisting
of titanium dioxide, zirconium dioxide, tin dioxide and aluminum oxide, and (b)
from 0.1% to 1.5% by weight, based on the weight of the component (a) and per m2/g
of specific surface area of the component (a), of vanadium pentoxide, applied to
the external surface of the support body.
