A “retreat-for-advance” strategy for effective oxidative biomass valorization by integrating self reduction

The electrosynthesis of 2,5-furandicarboxylic acid (FDCA) is hindered by the instability of 5-hydroxymethylfurfural (HMF) in alkaline media, causing carbon loss and low FDCA yield. Herein, a “retreat-for-advance” strategy is proposed, wherein HMF is first electro-reduced to stabilized 2,5-bis(hydroxymethyl)furan (BHMF) prior to its subsequent oxidation to FDCA (HMFRR to BHMFOR). The Cu-CoP-A bifunctional electrocatalyst enables efficient HMFRR at −162 mV_RHE (10 mA cm⁻²) and concurrent BHMFOR at 1.35 V_RHE (100 mA cm⁻²), which is attributed to Cu-induced electron redistribution and oxygen vacancies that synergistically reduce overpotentials by 171 mV (HMFRR) and 40 mV (BHMFOR). Strikingly, the integrated HMFRR-BHMFOR paired system delivers near-quantitative FDCA yields (98 %, surpassing the 51 % of conventional routes) coupled with an aggregate FE of 134 % (2.5-fold enhancement). Beyond performance metrics, techno-economic and life-cycle analyses demonstrate a 43 % reduction in FDCA minimum selling price ($7.3 kg⁻¹) alongside 40 % lower environmental impacts. This strategy establishes a universal paradigm for stabilizing aldehyde intermediates in biomass upgrading.