Upgrading of oxygenated compounds present in aqueous biomass-derived feedstocks over NbO_x-based catalysts

The influence of synthesis and post-synthesis procedures of different niobium oxides on their catalytic performance in the aqueous phase condensation of oxygenated compounds is studied. Hydrothermally synthesized niobium oxide with a pseudo-crystalline structure shows enhanced acid properties, surface area and consequently better catalytic activity than Nb₂O₅ prepared by other synthesis methods. The optimized NbO_x-based catalyst also demonstrates higher stability after several reuses compared to the Ce–Zr mixed oxide reference catalyst.