Patent ID: 6036880
Filing Date: 2000-03-14
Classification: B01J,C07C,Y02P

Abstract:
A niobium-containing aqueous solution for use in producing a niobium-containing oxide catalyst,wherein said niobium-containing oxide catalyst comprises an oxide of a plurality of active component elements including niobium and is for use in a catalytic oxidation or ammoxidation of propane or isobutane in the gaseous phase, and wherein said niobium-containing oxide catalyst is prepared by a process comprising mixing said niobium-containing aqueous solution with an aqueous mixture or aqueous mixtures containing compounds of active component elements of said oxide catalyst other than niobium, to thereby provide an aqueous compound mixture, and drying said aqueous compound mixture, followed by calcination,said niobium-containing aqueous solution comprising water having dissolved therein a dicarboxylic acid, a niobium compound and optionally ammonia, wherein the molar ratio (.alpha.) of said dicarboxylic acid to the niobium contained in said niobium compound satisfies the following relationship: 1.ltoreq.(.alpha.).ltoreq.4, and the molar ratio (.beta.) of said ammonia to the niobium contained in said niobium compound satisfies the following relationship: 0 .ltoreq.(.beta.).ltoreq.2.