Reactant adsorption modulation by Fe and K in Pt catalyst for highly effective CO preferential oxidation in practical conditions.

[Display omitted] • Fe and K were introduced into Pt/MOR catalysts to modulate the reactants adsorption in CO-PROX. • 1Pt0.1 K/Fe-MOR achieves 100% CO conversion and 60–70% CO 2 selectivity within 130–200 °C. • Fe improves the CO conversion by providing more oxygen vacancies to activate O 2. • K promotes the CO 2 selectivity by enhancing CO adsorption and weakening H 2 adsorption on Pt. Developing efficient and stable catalysts for preferential oxidation of CO (CO-PROX) within a wide temperature window is significant for the industrial hydrogen resource purification process. Herein, dual promoters of Fe and K were deliberately introduced to the mordenite supported Pt catalyst for optimizing the adsorption behaviors of reactants in CO-PROX. The optimal 1Pt0.1 K/Fe-MOR catalyst can achieve 100% CO conversion and 60–70% CO 2 selectivity (the ratio of CO/O 2 is 1:1) under the realistic application temperature range (130–200 °C), and remains catalytically stable during 65 h testing at 140 °C. A combination of detailed characterizations and density functional theory (DFT) simulations show that Fe species can avoid the co-adsorption of O 2 on the Pt sites by providing more oxygen vacancy to activate O 2 , while K species will further enhance the adsorption of CO and repulse the adsorption of H 2 on Pt surface. Therefore, the optimized adsorption of CO, O 2 and H 2 results in a total CO conversion and high CO 2 selectivity in high temperature range. [ABSTRACT FROM AUTHOR]