Dislocation-induced Strain in Bismuth Nanoparticles for improving Carbon Dioxide Electroreduction to Formic Acid.

Through a solid-electrolyte membrane electrode assembly (MEA) electrolyzer, CO₂ can be electrochemically reduced to feasibly produce liquid formic acid. However, there still lacks of the in-depth exploration into the catalyst design suitable for cathode membrane electrode as a key component in a solid-electrolyte MEA electrolyzer. Herein, a lattice strain-rich bismuth nanoparticle (D-Bi-NPS) integrated with anion exchange membrane is designed to produce formic acid, which can continuously produce formic acid with a concentration of 0.19 M for more than 74 hours at a current density of 100 mA·cm-2. By using this cathode membrane electrode, the Faradaic efficiency for formic acid can reach a maximum of 94.1%, with values exceeding 80% for the majority of the operational time. The improved performance of D-Bi-NPS is attributed to its abundant internal defects, which generate compressive strains that can dramatically accelerate interfacial electron transfer and optimize adsorption strength of intermediate. This study offers a novel approach for the design and development of solid-electrolyte MEA electrolyzer.