Simultaneous electrocatalytic reduction and oxidation of 5-hydroxymethylfurfural (HMF) is crucial for biomass refineries. Herein, we report the unprecedentedly high efficiency of the nearly complete conversion of biomass-derived HMF to value-added products, achieving >
95% selectivity at -0.4 V vs RHE by pairing electrocatalytic reduction and oxidation (PERO) reactions in a single electrochemical cell. At the cathode, we achieved 99% conversion of HMF to 2,5-dihydroxymethylfuran (DHMF) in ∼99% yield under mild conditions using a PtRu alloy. At the anode, we observed 99% conversion of HMF, nearly perfect selectivity for the oxidative product 2,5-furandicarboxylic acid (FDCA), and 100% Faradaic efficiency on a NiCo(OOH)