Abstract: The invention relates to a process for producing a catalyst for gas-phase oxidations, which comprises weighing a particulate inert support having a total mass of Msupport into a fluidized-bed apparatus, providing an aqueous suspension of a catalytically active material or sources therefor and a binder having a binder content of Bsusp, fluidizing the inert support by introduction of a gas stream heated to a temperature of Tgas at a flow rate of Qgas, and spraying the suspension at a rate of Qsusp onto the fluidized inert support. When Qgas, Qsusp, Bsusp, Msupport and Tgas are selected within the ranges 3000?Qgas [m3/h]?9000, 1000?Qsusp [g/min]?3500, 2?Bsusp [% by weight]?18, 60?Msupport [kg]?240. 75?Tgas [° C.]?120 so that a parameter K defined as K=0.020 Qgas?0.055 Qsusp+7.500 Bsusp?0.667 Msupport+2.069 Tgas?7 satisfies the relationship 127.5?K?202, high-quality coatings can be produced and the formation of twins made up of support particles adhering to one another can be avoided.