Maleic anhydride is an important intermediate in the chemical industry. It is structurally similar to furfural, a compound that can be produced from agricultural waste and used as a renewable chemical feedstock.

Yugen Zhang and colleagues, Institute of Bioengineering and Nanotechnology, Singapore, have developed an efficient gas phase oxidation of furfural to maleic anhydride. The team developed a plate vanadium phosphorous oxide (VPO) catalyst (pictured), synthesized by a hydrothermal method. The catalyst synthesis is based on V₂O₅ and H₃PO₄ as starting materials and glucose as a green reducing agent.

Compared with conventional VPO catalysts, the synthesized material shows improved activity for the oxidation of furfural, as well as better selectivity and stability. The catalyst achieves ca. 90 % yield of maleic anhydride at 10 vol% furfural in the gas feed and at 360 °C reaction temperature, using air as the oxidant. The researchers attribute the improved catalytic properties to a preferentially exposed 200 crystal plane, which could play a key role in the reaction.

• Highly Efficient Gas Phase Oxidation of Renewable Furfural to Maleic Anhydride over Plate VPO Catalyst,
  Yugen Zhang, Xiukai Li, Jogie Ko,
  ChemSusChem 2017.
  https://doi.org/10.1002/cssc.201701866