Stable, active CO<sub>2</sub> reduction to formate via redox-modulated stabilization of active sites.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 34471135.
- Also identified by DOI 10.1038/s41467-021-25573-9 and PMC identifier 8410779.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Electrochemical reduction of CO<sub>2</sub> (CO<sub>2</sub>R) to formic acid upgrades waste CO<sub>2</sub>; however, up to now, chemical and structural changes to the electrocatalyst have often led to the deterioration of performance over time. Here, we find that alloying p-block elements with differing electronegativities modulates the redox potential of active sites and stabilizes them throughout extended CO<sub>2</sub>R operation. Active Sn-Bi/SnO<sub>2</sub> surfaces formed in situ on homogeneously alloyed Bi<sub>0.1</sub>Sn crystals stabilize the CO<sub>2</sub>R-to-formate pathway over 2400 h (100 days) of continuous operation at a current density of 100 mA cm<sup>-2</sup>. This performance is accompanied by a Faradaic efficiency of 95% and an overpotential of ~ -0.65 V. Operating experimental studies as well as computational investigations show that the stabilized active sites offer near-optimal binding energy to the key formate intermediate *OCHO. Using a cation-exchange membrane electrode assembly device, we demonstrate the stable production of concentrated HCOO<sup>-</sup> solution (3.4 molar, 15 wt%) over 100 h.