Promotion Effect of Alkali Metals on Pt/Co-CeO₂ Nanorod Catalysts for Low-Temperature CO Oxidation

Cerium-based materials show great potential in the field of CO catalytic oxidation. Introducing transition metals into CeO2 can effectively increase its oxygen vacancy concentration and adjust the surface and interface structures of the catalyst. Additionally, optimizing the electronic structure of the Pt active site through alkali metals can further improve the CO oxidation activity and stability. In this work, systematic characterization techniques including XRD, TEM, and BET confirmed the uniform dispersion of alkali metals and noble metal Pt on Co-CeO2 nanorods. Surface studies revealed that the alkali metals facilitated electron transfer from the support to the Pt active sites. In addition, in situ DRIFTS spectroscopy confirmed that CO catalysis oxidation on the Pt/K/Co-CeO2 catalyst predominantly follows the MvK mechanism, with carbonates serving as key intermediates. The activation of gas-phase O2 by abundant oxygen vacancies facilitates the generation of active oxygen species, thereby enhancing the level of CO oxidation. This study reveals promising perspectives for improving the catalysis activity of supported metal catalysts in CO oxidation through alkali metal modification.