A method for manufacturing of an attrition resistant vanadium/phosphorous
oxide catalyst involving forming an aqueous slurry comprising;
vanadium/phosphorous oxide catalyst or vanadium/phosphorous oxide catalyst
precursor particles, an aqueous solution of H.sub.3 PO.sub.4, and
optionally an aqueous colloidal silica sol, an aqueous polysilicic acid
solution or mixture thereof and then spray drying the slurry to form
attrition resistant catalyst precursor followed by calcining/activating
the spray dried precursor. Such a catalyst is particularly useful in
oxidation processes such as the catalytic air oxidation of butane to
maleic anhydride.
