Pyromellitic dianhydride catalyst and preparation method thereof

Abstract

The invention provides a pyromellitic dianhydride catalyst and a preparation method thereof, relates to a catalyst and the preparation method and solves the problems of low catalyst yield and low selectivity of the conventional gaseous oxidation method for preparing pyromellitic dianhydride. The catalyst consists of an active ingredients and a carrier, wherein the active ingredients consist of V2O5, TiO2, P2O5, Sb2O3 and alkali metal oxides. The method comprises the following steps of: 1, weighing; 2, adding an antimony source and a vanadium source into oxalic acid solution with stirring to obtain vanadyl oxalate solution; 3, adding a phosphorus source, the antimony source and alkali metal salt into the vanadyl oxalate solution, uniformly mixing, then adding a titanium source, adding polyvinyl acetate emulsion and then pulping and grinding to obtain size; and 4, adding the carrier into a revolving drum of spray painting equipment, heating and spraying the size on the carrier, putting into a Muffle furnace to carry out air purge and cooling to obtain the catalyst. The catalyst is used for catalysis and preparation of pyromellitic dianhydride.

Description

technical field

[0001] The invention relates to a catalyst and a preparation method thereof. Background technique

[0002] Pyromellitic dianhydride (PMDA) is an important chemical raw material, mainly used as a monomer of polyimide, polyimidazole and other heat-resistant resins, powder coating matting agent intermediates, pharmaceutical intermediates, and environmental protection materials. Oxygen resin curing agent, etc., the products made of it have been widely used in the cutting-edge technology departments of aviation, aerospace, electronic industry and other fields.

[0003] At present, the production method of pyromellitic dianhydride mostly adopts durene with vanadium-titanium oxide as a catalyst, and uses air catalytic oxidation to obtain crude product pyromellitic dianhydride (crude anhydride for short), which is further purified by hydrolysis and recrystallization. Get fine pyromellitic dianhydride (referred to as homoanhydride).

[0004] The existing gas-phase o...