A process for producing a catalyst body includes providing titanium dioxide, tungsten trioxide, vanadium pentoxide, aluminum oxide, and/or silicon oxide for the catalyst body. A kneadable and/or shapable compound is processed to form a shaped body by extrusion or by coating of a support body. The shaped body is dried and is calcined to form an active compound. The calcined shaped body is artificially aged by a final heat treatment at a temperature higher than the calcination temperature to produce a catalyst body having a high resistance to deactivation at high temperatures. The starting materials include from 65 to 95% by weight of titanium dioxide, 2 to 30% by weight of tungsten trioxide, 0 to 2% by weight of vanadium pentoxide, preferably, less than 1.5%, 0.1 to 10% by weight of aluminum oxide, and 0.1 to 10% by weight of silicon dioxide. The final heat treatment is done is at 660 to 700° C., drying is at 20 to 100° C. prior to calcination, and calcination is at 400° C. to less than 700° C.