Divergent Paths, Same Goal: A Pair-Electrosynthesis Tactic for Cost-Efficient and Exclusive Formate Production by Metal-Organic-Framework-Derived 2D Electrocatalysts.

Abstract

Electrosynthesis of formic acid/formate is a promising alternative protocol to industrial processes. Herein, a pioneering pair-electrosynthesis tactic is reported for exclusively producing formate via coupling selectively electrocatalytic methanol oxidation reaction (MOR) and CO2 reduction reaction (CO2 RR), in which the electrode derived from Ni-based metal-organic framework (Ni-MOF) nanosheet arrays (Ni-NF-Af), as well as the Bi-MOF-derived ultrathin bismuthenes (Bi-enes), both obtained through an in situ electrochemical conversion process, are used as efficient anodic and cathodic electrocatalysts, respectively, achieving concurrent yielding of the same high-value product at both electrodes with greatly reduced energy input. The as-prepared Ni-NF-Af only needs quite low potentials to reach large current densities (e.g., 100mAcm-2 @1.345V)with ≈100% selectivity for anodic methanol-to-formate conversion. Meanwhile, for CO2 RR in the cathode, the as-prepared Bi-enes can simultaneously exhibit near-unity selectivity, large current densities, and good stability in a wide potential window toward formate production. Consequently, the coupled MOR//CO2 RR system based on the distinctive MOF-derived catalysts displays excellent performance for pair-electrosynthesis of formate, delivering high current densities and nearly 100% selectivity for formate production in both the anode and the cathode. This work provides a novel way to design advanced MOF-derived electrocatalysts and innovative electrolytic systems for electrochemical production of value-added feedstocks.