Robust\nBi Metal–Organic Framework-Derived Catalyst\nfor the Selective Electroreduction of CO<sub>2</sub> to Formate at\nCurrent Densities up to 1 A cm<sup>–2</sup> in Gas Diffusion\nElectrodes

Electrochemical\nreduction of CO<sub>2</sub> to useful products\nrequires selective and stable catalysts that can be easily synthesized\nand are cost-effective. In this work, we investigate the Bi CAU-17\nmetal–organic framework (MOF) synthesized by a novel and scalable\nmethod to generate in situ highly active Bi<sub>2</sub>O<sub>2</sub>CO<sub>3</sub> catalyst for CO<sub>2</sub> electroreduction to formate\nin either KHCO<sub>3</sub> or KOH electrolytes. The Bi CAU-17-derived\ncatalyst provides high faradaic efficiencies toward formate (FE<sub>HCOO</sub><sup>–</sup> = 85–100%) at current densities\nup to 1 A cm<sup>–2</sup> in a gas diffusion electrode with\na low catalyst loading (0.5 mg cm<sup>–2</sup>). Comparative\nexperiments between commercial and in situ generated Bi<sub>2</sub>O<sub>2</sub>CO<sub>3</sub> from Bi CAU-17 showed that the latter\nhas superior catalytic performance at high current densities (>300\nmA cm<sup>–2</sup>) and with stable activity after 26 h of\ncontinuous electrolysis at 200 mA cm<sup>–2</sup> in the pH\nrange 8–14. These results highlight the importance of generating\nin situ active Bi/Bi–O sites that promote the selective reduction\nof CO<sub>2</sub> to formate.