A process for regenerating a deactivated heteropolymolybdophosphoric acid catalyst

摘要

The present invention provided a process for regenerating a deactivated heteropolymolybdophosphoric acid catalyst comprising the steps of grinding the deactivated catalyst into particles having a particle size of 40 mesh or less, mixing same with a mixture consisting of aqua ammonia, an aqueous solution containing ammonium ion and organic auxiliaries and kneading same in a kneader to obtain a paste, drying the paste and molding into cylindrical particle with a through hole in its longitudinal axis, and heating in atmosphere at 350 - 450°C for 1 ~ 10 hours to produce the generated catalyst. The catalytic capacity of such a catalyst having keggin structure of heteropoly acid fully recovered is fully restored for selective oxidation of lower unsaturated aldehydes (such as acrolein or isobutyraldehyde) to produce unsaturated acids. The regeneration is conducted under mild condition by a simple and easy process with good reproducibility.