Highly Ordered Mesoporous Co3O4 Electrocatalyst for Efficient, Selective, and Stable Oxidation of 5‐Hydroxymethylfurfural to 2,5‐Furandicarboxylic Acid

Electrochemical oxidation of biomass substrates to valuable bio‐chemicals is highly attractive. However, the design of efficient, selective, stable, and inexpensive electrocatalysts remains challenging. Here it is reported how a 3D highly ordered mesoporous Co3O4/nickel foam (om‐Co3O4/NF) electrode fulfils those criteria in the electrochemical oxidation of 5‐hydroxymethylfurfural (HMF) to value‐added 2,5‐furandicarboxylic acid (FDCA). Full conversion of HMF and an FDCA yield of >99.8 % are achieved with a faradaic efficiency close to 100 % at a potential of 1.457 V vs. reversible hydrogen electrode. Such activity and selectivity to FDCA are attributed to the fast electron transfer, high electrochemical surface area, and reduced charge transfer resistance. More impressively, remarkable catalyst stability under long‐term testing is obtained with 17 catalytic cycles. This work highlights the rational design of metal oxides with ordered meso‐structures for electrochemical biomass conversion. Electrochemical biomass upgrading: Highly ordered mesoporous Co3O4 is an efficient, selective, stable, and inexpensive electrocatalyst for 5‐(hydroxymethyl)furfural (HMF) oxidation, achieving a 2,5‐furandicarboxylic acid (FDCA) yield of >99.8 % with a faradaic efficiency close to 100 %. Remarkable catalyst stability is obtained with 17 catalytic cycles.