catalyst comprising a tetraalkylammonium polyoxoanion the poa comprises a one or two central atoms x selected from the group consisting of group iiia via elements of the periodic table b a framework comprising 17 to 61 oxygen atoms o and 4 to 19 framework metal atoms m selected from the group consisting of molybdenum tungsten and vanadium and combinations thereof c one or more atoms m 39 selected from the group consisting of ruthenium and first row transition metals substituted for one or more framework metal oxygen units m u2550 o in the framework and d a sufficient number e of cations to electronically balance the charge e of said polyoxoanion wherein at least one of said cations comprises tetraalkylammonium cation these poas may be of the keggin or dawson structures where there are more than one m 39 atom substituted for m u2550 o units in the framework the m 39 may be randomly substituted or geometrically controlled substitutions these poas may be prepared according to the method taught by ellis et al u s pat no 5 091 354 in the catalysts useful in the present invention the central atom x is preferably one atom but may be two.