摘要:
Catalytically active multielement oxide materials which contain at least one of the elements Nb and W and the elements Mo, V and Cu are prepared by a process in which an intimate dry blend containing ammonium ions is prepared and said dry blend is subjected to a thermal treatment in an atmosphere having a low molecular oxygen content at elevated temperatures, a portion of the ammonium ions contained in the intimate dry blend being decomposed with liberation of ammonia and the oxygen content of the thermal treatment atmosphere being increased in the course of the thermal treatment.
摘要:
In a process for the thermal treatment of the precursor material of a catalytically active material in a rotary tube furnace through which a gas stream flows, at least a proportion of the gas stream flowing through the rotary tube furnace is circulated, and the associated rotary tube furnace apparatus and tube-bundle reactors for the partial gas-phase oxidation of acrolein to acrylic acid are loaded with catalysts whose catalytically active material is obtainable by the process for the thermal treatment.