A comparative study proposing performance benchmarks for convoying industrial CO2-to-formate electroconversion

Abstract

Selecting suitable electrocatalytic benchmarks can greatly enhance electrocatalyst design and better assess their performance and potential applications. However, the absence of standardized electrocatalytic benchmarks bridging laboratory innovation to industrial implementation hinders the development of pH-universal CO₂-to-formate conversion systems that meet industrial-grade current densities (> 200 mA cm^–2), Faradaic efficiencies (FE > 90 %), and long-term stability. Herein, through a systematic evaluation of commercial bismuth-based chemicals (metal, oxide, salts) for CO₂ electroreduction, we demonstrated that bismuth salts (e.g., Bi(NO₃)₃) as precursors for material development, can emerge as the universal performance benchmarks across all pH conditions (acidic, neutral, and alkaline). Concretely, in various electrolytic environments for formate production, these bismuth salts-coated electrodes generally exhibit exceeding 90 % FE, large current densities, low onset potentials and potential operational stability. Moreover, a comparative analysis with In/Sn/Pb analogues profoundly elucidates the general benchmarking feasibility of bismuth salts in facilitating CO₂-to-formate electroconversion. This work establishes a screening paradigm of formate-targeted electrocatalytic materials, which can assess and guide the design of practical CO₂ electrocatalysts for sustainable formate production at industrial scales.