. "Our catalyst is suitably prepared in organic solvents by slurrying vanadium compounds and metals or metal oxides such as molybdenum oxide, zinc oxide, uranium oxide, tungsten oxide, tin oxide, bismuth oxide, titanium oxide, niobium oxide, antimony oxide and cobalt oxide in organic solvents having from about 2 to 10 carbon atoms, preferably organic ether solvents." . . . . .