Preferential Cleavage of C–C Bonds in Glycerol Electrooxidation via Multi-Site Collaboration within Ultrathin Medium-Entropy Nanosheets

The glycerol electro-oxidation reaction (GEOR) to formate represents an attractive technology for the concurrent production of hydrogen and the valorization of biomass. However, the intricate pathway of GEOR and the high cost associated with noble metal electrocatalysts hinder its progress. Herein, ultrathin CuCoNiW medium-entropy oxide nanosheets (CuCoNiWOx UNS) serve as an effective noble-metal-free catalyst for this transformation. It delivers a high mass activity mass activity of 632.9 mA mgmetal–1, a low potential of 1.0 V vs RHE at 10 mA cm–2, and a formate selectivity of 83.1%, with remarkable stability over 40 h. The high performance is attributed to the distinct roles of each metal within the medium-entropy structure: subsurface W atoms ensure structural stability; Co and Ni sites optimize the adsorption of glycerol and intermediates; and Cu sites promote C–C bond cleavage. The reaction pathway involves the sequential conversion of glycerol to glyceraldehyde, glyceraldehyde to glycolaldehyde/formate, and glycolaldehyde to formate. These findings emphasize the efficacy of implementing medium-entropy structures as a viable strategy for biomass electrooxidation reactions.