Efficient Catalytic Conversion of 5-Hydroxymethylfurfural to 2,5-Furandicarboxylic Acid over Ruthenium Cluster-Embedded Ni(OH) 2 Catalyst.

5-Hydroxymethylfurfural (HMF) can be oxidized to 2,5-furandicarboxylic acid (FDCA) for the production of biorenewable plastics to replace fossil resourced polyethylene terephthalate (PET). Development of a highly efficient electrocatalyst using renewable electricity as energy input is highly desired. In this work, Ru cluster-embedded Ni(OH) 2 nanosheets [Ru/Ni(OH) 2 ] were synthesized and exploited as electrochemical catalysts for the conversion of HMF to FDCA. Ru/Ni(OH) 2 exhibited significantly improved current density (40 mA cm -2 at 1.41 V vs. reversible hydrogen electrode) of over 7.7 times in comparison with Ni(OH) 2 , and nearly 100 % conversion degree for HMF and 98.5 % selectivity towards FDCA were obtained. Operando Raman experiments revealed the catalysis was facilitated by the interconversion between Ni 3+ and Ni 2+ . Density functional theory calculations further revealed the effect of Ru clusters of Ni(OH) 2 , thereby promoting HMF adsorption capacity on Ni sites to boost HMF oxidation activity. This work provides a novel strategy using Ru clusters to modify earth abundant Ni based catalyst for HMF oxidation to obtain high-value biomass-derived products.