PREPARATION OF VANADIUM PHOSPHORUS CATALYST USING A MIXED PHOSPHORUS SOURCE

摘要

Oxidn. catalysts contg. mixed V and P oxides are prepd. as follows; (a) a V (5+) cpd. (I) is added to a liq. medium capable of reducing it; (b) the redn. of at least some (I) is effected to give V (4+); (c) a mixed P component (II) is added before or after the redn. of (I); and (d) the catalyst precursor is recovered, dried, and calcined. (II) is H3PO4/pyrophosphoric acid. The prepd. catalysts show increased processability (using H3PO4 alone, fine powders tend to be produced), and have increased activity in affording maleic anhydride from 4C hydrocarbons in high yield and selectivity.