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

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% CO2 selectivity (the ratio of CO/O-2 is 1:1) under the realistic application temperature range (130-200 degrees C), and remains catalytically stable during 65 h testing at 140 degrees 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 CO2 selectivity in high temperature range.

Automated summary

Developing efficient and stable catalysts for preferential oxidation of CO (CO-PROX) is crucial for industrial hydrogen resource purification. The introduction of dual promoters, Fe and K, optimizes the adsorption behaviors of reactants and achieves high CO conversion and CO2 selectivity under realistic application temperature range.