Autogenetic Carbon Oxyanions Enable Interfacial OH <sup>−</sup> Deconfinement for Reinforced Biomass Electrooxidation over Wide Potential Window
Keping Wang, Mei Wu, Yan Zhang, Binbin Jiang, Yaqiong Su, Song Yang, Xihong Lu, Hu Li
Abstract
Abstract The preferential adsorption toward OH − on the anode most likely blocks the accessibility of organic molecules and triggers competitive oxygen evolution reaction (OER), typically precipitating a narrow potential window. Here, an OH − deconfinement strategy enabled by CO 3 2− self‐transformed from C 2 O 4 2− on metallic nickel oxalate (NiC 2 O 4 ) for efficient synthesis of bioplastic monomer 2,5‐furanedicarboxylic acid (FDCA) with faradaic efficiency of >95% via electrocatalytic 5‐hydroxymethylfurfural (HMF) oxidation reaction (e‐HMFOR) at a wider potential window of 1.38–1.56 V RHE , outperforming state‐of‐the‐art Ni‐based electrocatalysts is presented. In situ, tests corroborate that the construction of NiOOH with surface‐adsorbed CO 3 2− (NiOOH‐CO 3 2− ) from NiC 2 O 4 can be facilitated by self‐liberating CO 3 2− . The CO 3 2− ions serving as an electric field engine can effectively weaken OH − coverage through electrostatic repulsion and enhance HMF adsorption at the NiOOH‐CO 3 2− surface, thereby heightening e‐HMFOR while inhibiting OER. Computational results further indicate that the CO 3 2− on NiOOH hoists the energy barrier of oxygen intermediate conversion (O* → OOH*) to suppress OER but promotes the e‐HMFOR kinetics. The precise modulation of OH − adsorption behavior on the electrocatalyst offers a powerful kit for boosting the oxidative upgrading process while circumventing the competing reaction OER.