Enhanced CO Oxidation on PtO x Raft Species Synthesized via Citric Acid‐Assisted Electrostatic Adsorption

Abstract Platinum‐based catalysts have attracted considerable attention for CO oxidation, with their activity critically dependent on the nanostructures of Pt species. Herein, raft‐structured PtO x species on CeO 2 support (Pt/CeO 2 ‐CA) were successfully prepared via a citric acid‐assisted strong electrostatic adsorption (SEA) method, which leveraged competitive adsorption between noble metal precursors and organic compounds. The Pt/CeO 2 ‐CA catalyst exhibits a T 50 (temperature for 50% CO conversion) over 120 °C lower than those of Pt single atoms and PtO x clusters‐based catalysts, and the lowest apparent activation energy among the catalysts investigated, as well as reported analogues, demonstrating its excellent activity in CO oxidation. Combined catalyst characterization and density functional theory (DFT) calculations demonstrate enhanced CO adsorption on PtO x rafts with respect to Pt/CeO 2 reference catalysts composed of Pt single atoms or PtO x clusters, and favored CO interaction with O* atoms from PtO x rafts and the CeO 2 surface. We propose that this mitigates CO poisoning effects by circumventing competitive adsorption with O 2 , thereby accelerating the catalytic reaction. Our findings highlight promising design strategies for tuning the morphology of supported noble metal (oxide) nanostructures to further enhance their catalytic performances.