| abstract |
A catalyst complex useful for converting normal C 4 hydrocarbons to maleic anhydride in vapor phase comprising as components vanadium, phosphorus, copper, an element selected from the Group of Te, Zr, Ni, Ce, W, Pd, Ag, Mn, Cr, Zn, Mo, Re, Sm, La, Hf, Ta, Th, Co, U, and Sn preferably with an alkali or alkaline earth metal. |