Unraveling distinct effects between CuO<sub>x</sub> and PtCu alloy sites in Pt-Cu bimetallic catalysts for CO oxidation at different temperatures.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38961110.
- Also identified by DOI 10.1038/s41467-024-49968-6 and PMC identifier 11222431.
- 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
In situ exploration of the dynamic structure evolution of catalysts plays a key role in revealing reaction mechanisms and designing efficient catalysts. In this work, PtCu/MgO catalysts, synthesized via the co-impregnation method, outperforms monometallic Pt/MgO and Cu/MgO. Utilizing quasi/in-situ characterization techniques, it is discovered that there is an obvious structural evolution over PtCu/MgO from Pt<sub>x</sub>Cu<sub>y</sub>O<sub>z</sub> oxide cluster to PtCu alloy with surface CuO<sub>x</sub> species under different redox and CO oxidation reaction conditions. The synergistic effect between PtCu alloy and CuO<sub>x</sub> species enables good CO oxidation activity through the regulation of CO adsorption and O<sub>2</sub> dissociation. At low temperatures, CO oxidation is predominantly catalyzed by surface CuO<sub>x</sub> species via the Mars-van Krevelen mechanism, in which CuO<sub>x</sub> can provide abundant active oxygen species. As the reaction temperature increases, both surface CuO<sub>x</sub> species and PtCu alloy collaborate to activate gaseous oxygen, facilitating CO oxidation mainly through the Langmuir-Hinshelwood mechanism.