Expanding the scope of biogenic substrates for the selective production of formic acid from water-insoluble and wet waste biomass

The selective oxidation of complex, water-insoluble and wet biomass from second and third generation to formic acid including effective catalyst recycling is reported. Additionally, the relevance and limits of potential contaminants are illustrated by different experimental approaches. By using a very robust homogeneous polyoxometalate catalyst in aqueous solution, molecular oxygen as an oxidant and an acid as a solubilizer, it is possible to convert different lignocellulosic and algae feedstock into formic acid and pure carbon dioxide. The applied green oxidation system benefits from its low reaction temperature (below 100 °C) and its very selective nature. Furthermore, catalyst recycling over three batches has been successfully carried out.