Scalable synthesis of coordinatively unsaturated metal-nitrogen sites for large-scale CO<sub>2</sub> electrolysis.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37072410.
- Also identified by DOI 10.1038/s41467-023-36688-6 and PMC identifier 10113237.
- 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
Practical electrochemical CO<sub>2</sub>-to-CO conversion requires a non-precious catalyst to react at high selectivity and high rate. Atomically dispersed, coordinatively unsaturated metal-nitrogen sites have shown great performance in CO<sub>2</sub> electroreduction; however, their controllable and large-scale fabrication still remains a challenge. Herein, we report a general method to fabricate coordinatively unsaturated metal-nitrogen sites doped within carbon nanotubes, among which cobalt single-atom catalysts can mediate efficient CO<sub>2</sub>-to-CO formation in a membrane flow configuration, achieving a current density of 200 mA cm<sup>-2</sup> with CO selectivity of 95.4% and high full-cell energy efficiency of 54.1%, outperforming most of CO<sub>2</sub>-to-CO conversion electrolyzers. By expanding the cell area to 100 cm<sup>2</sup>, this catalyst sustains a high-current electrolysis at 10 A with 86.8% CO selectivity and the single-pass conversion can reach 40.4% at a high CO<sub>2</sub> flow rate of 150 sccm. This fabrication method can be scaled up with negligible decay in CO<sub>2</sub>-to-CO activity. In situ spectroscopy and theoretical results reveal the crucial role of coordinatively unsaturated metal-nitrogen sites, which facilitate CO<sub>2</sub> adsorption and key *COOH intermediate formation.