Formic Acid Production via One-Pot Hydrolysis-Oxidation of Starch over Quaternary Ammonium Salts of Vanadium-Containing Keggin-Type Heteropoly Acids

Bifunctional solid acidic quaternary ammonium salts of Keggin-type vanadium-containing heteropoly acids, such as R3.5H0.5PVMo11O40 (R: (C2H5)4N, (C4H9)4N, (C6H13)4N), and [(C4H9)4N]4.5H0.5SiW11VO40, are capable of one-pot hydrolysis-oxidationconversion (OxFA-processing) of starch to biogenic formic acid. The impact of the reaction conditions and catalyst type was revealed. The highest formic acid yield of 50% was achieved over the best [(C2H5)4N]3.5H0.5PVMo11O40 catalyst, which was active and stable in seven reaction cycles. The kinetic computational model, which described formic acid formation well, was proposed in the presence of the most active [(C2H5)4N]3.5H0.5PVMo11O40 catalyst.