Photoswitchable Catalytic Aerobic Oxidation of Biomass-Based Furfural: A Selective Route for the Synthesis of 5-Hydroxy-2(5H)-furanone and Maleic Acid by Using the CdS/MOF Photocatalyst
Saeede Saki, Mona Hosseini‐Sarvari, Yanlong Gu, Tianjian Zhang
Abstract
Selective oxidation of furfural has become important for the synthesis of pharmaceutical intermediates and chemical industries. The development of effective methods for biomass valorization is a very attractive subject. Here, we performed an initial investigation into the photocatalytic selective oxidation of furfural to maleic acid (MA) as a valuable chemical and the vital bioactive intermediate 5-hydroxy-2(5H)-furanone (HFO). In this work, MOFs-based Ti (NH 2 -MIL-125) was modified with the easy method by introducing the proper amount of CdS (2.5%) on the surface of NH 2 -MIL-125. The photocatalyst developed in this work performed best and gave high HFO (52%), MA (90%) selectivity, and high conversion (>90%) of furfural under various reaction conditions. The CdS (2.5%)/NH 2 -MIL-125 nanocomposite also showed a long-term stability. Synergistic interactions between the active surface of NH 2 -MIL-125 (which uses organic linkers as an antenna) and the active sites of CdS may result in enhancement of the photocatalytic activity of the CdS (2.5%)/NH 2 -MIL-125 photocatalyst. An analysis of the mechanism revealed that HFO and MA were produced from furfural through a series of multistep reactions, including oxidation, decarboxylation, and ring opening.