Catalyst for the oxidation of a mixed aldehyde feedstock to methacrylic acid and methods for making and using same

Abstract

A heteropolyacid catalyst for oxidation of isobutyraldehyde, methacrolein or mixtures or combinations thereof to methacrylic acid is disclosed where the heteropolyacid catalyst includes at least molybdenum (Mo), phosphorus (P), vanadium (V), and a first component including bismuth (Bi) and/or boron (B). The heteropolyacid catalyst can also optionally include a second component including potassium (K), rubidium (Rb), cesium (Cs), and/or thallium (Tl) and optionally a third component including antimony (Sb), cerium (Ce), niobium (Nb), indium (In), iron (Fe), chromium (Cr), cobalt (Co), nickel (Ni), manganese (Mn), arsenic (As), silver (Ag), zinc (Zn), germanium (Ge), gallium (Ga), zirconium (Zr), magnesium (Mg), barium (Ba), lead (Pb), tin (Sn), titanium (Ti), aluminum (Al), silicon (Si), tantalum (Ta), tungsten (W), and/or lanthanum (La). The heteropolyacid catalyst can also include an ammonium-containing compound designed to increase a value of medium pores in the final heteropolyacid catalyst. A method for oxidizing isobutanal to methacrylic acid using the heteropolyacid catalyst is also disclosed.