Uncovering near-free platinum single-atom dynamics during electrochemical hydrogen evolution reaction.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32098951.
- Also identified by DOI 10.1038/s41467-020-14848-2 and PMC identifier 7042219.
- 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
Single-atom catalysts offering intriguing activity and selectivity are subject of intense investigation. Understanding the nature of single-atom active site and its dynamics under working state are crucial to improving their catalytic performances. Here, we identify at atomic level a general evolution of single atom into a near-free state under electrocatalytic hydrogen evolution condition, via operando synchrotron X-ray absorption spectroscopy. We uncover that the single Pt atom tends to dynamically release from the nitrogen-carbon substrate, with the geometric structure less coordinated to support and electronic property closer to zero valence, during the reaction. Theoretical simulations support that the Pt sites with weakened Pt-support interaction and more 5d density are the real active centers. The single-atom Pt catalyst exhibits very high hydrogen evolution activity with only 19 mV overpotential in 0.5 M H<sub>2</sub>SO<sub>4</sub> and 46 mV in 1.0 M NaOH at 10 mA cm<sup>-2</sup>, and long-term durability in wide-pH electrolytes.