 A Keggin-type polyoxometalate (H5PV2Mo10O40) is used as the homogeneous catalyst to convert sugars, wood, waste paper, or cyanobacteria to formic acid and CO2 as the sole byproduct.Yields of up to 53% formic acid can be achieved.In the laboratory, formic acid can be obtained by heating oxalic acid in glycerol and extraction by steam distillation.