Single-atoms Ru/NiFe layered double hydroxide electrocatalyst: Efficient for oxidation of selective oxidation of 5-hydroxymethylfurfural and oxygen evolution reaction

The adsorption performance modulation of catalysts on reactants is effective for the improvement of catalytic oxidation reactions. Ru is beneficial for adsorption of products. Here, the single Ru atoms were supported on NiFe layered double hydroxide (LDH) (Ru0.3/NiFe) to enhance the adsorption capacity of catalyst using a twostep electrodeposition method. Ru0.3/NiFe was used in the oxygen evolution reaction (OER) and the selective oxidation of 5-hydroxymethylfurfural (HMFOR). Ru0.3/NiFe showed extremely low overpotential (243 mV at 10 mA cm(-2)) and excellent durability in OER. Ru0.3/NiFe exhibits excellent HMF conversion (99.43%), 2,5-furan dicarboxylic acid (FDCA) selectivity (99.24%) and yield (98.68%) in HMFOR. The possible HMFOR reaction pathway was further studied, revealing that the load of Ru enhances the path from HMF to DFF, thereby improving the yield of FDCA. Both the outcomes of experimental findings and density functional theory (DFT) calculations indicate that increasing the composition of Ru optimizes the adsorption energy of HMF compared to NiFe, allowing FeNiOOH to more efficiently capture protons and electrons in HMFOR.