Ampere-Level Electrolytic Coproduction of Formate with Coupled Carbon Dioxide Reduction and Selective Methanol Oxidation
Shengtang Liu, Bailin Tian, Xinrui Xu, Xinzhu Wang, Pan Ran, Yamei Sun, Jianghua Wu, Aoqian Qiu, Fangyuan Wang, Lingyu Tang, Jing Ma, Mengning Ding
Abstract
The electrocatalytic oxidation of small organic molecules presents a compelling approach for environmentally friendly and value-added chemical production, especially when coupled with high-efficiency carbon dioxide reduction. However, significant challenges persist in achieving industrial-scale current densities while ensuring optimal selectivity, activity, and cycle stability of the electrocatalyst. Here, we report the high performance of the Au/NiOOH@Ni heterojunction foam electrode in selective methanol oxidation, which efficiently pairs with cathodic carbon dioxide reduction to reach ampere-level coelectrolytic production of formate. The Au/NiOOH@Ni foam demonstrated ∼100% Faraday efficiency in the high current density range of 200–1200 mA/cm 2 during half-cell methanol oxidation, and a total FE formate exceeding 180% was achieved under 1.20 A/cm 2 using a coelectrolytic flow cell. In situ mechanistic investigations and theoretical calculations revealed that Au/NiOOH heterojunctions promote the formation and stabilization of high-valence active Ni III/IV OOH under both as-prepared and operando conditions through the interfacial Ni IV -O*-Au structure, which continuously provides abundant active sites and oxygen sources (from partial water oxidation) for methanol-to-formate conversion while constructing a stable and efficient catalytic environment.