Evidence for the stabilization of FeN<sub>4</sub> sites by Pt particles during acidic oxygen reduction.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40640168.
- Also identified by DOI 10.1038/s41467-025-61806-x and PMC identifier 12246215.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
While Fe-N-C materials have shown promising initial oxygen reduction reaction (ORR) activity, they lack durability in acidic medium. Key degradation mechanisms include FeN<sub>4</sub> site demetallation and deactivation by reactive oxygen species. Here we show for mainstream Fe-N-Cs that adding 1 wt.% Pt nanoparticles via a soft polyol method results in well-defined and stable Pt/Fe-N-C hybrids. The Pt addition strongly reduces the H<sub>2</sub>O<sub>2</sub> production and Fe leaching rate during ORR, while post mortem Mössbauer spectroscopy reveals that the highly active but unstable Fe(III)N<sub>4</sub> site is partially stabilized. The similar H<sub>2</sub>O<sub>2</sub> electroreduction activity of Pt/Fe-N-C and Fe-N-C and other analyses point toward a long-distance electronic effect of Pt nanoparticles in stabilizing FeN<sub>4</sub> sites. Computational chemistry reveals that spin polarization of distant Pt atoms mitigates the structural changes of FeN<sub>4</sub> sites upon adsorption of oxygenated species atop Fe, especially in high-spin state.