Investigation of concentration hysteresis in methane oxidation on bimetallic Pt–Pd/Al2O3 catalyst by in situ XPS and mass spectrometry

A combination of in situ XPS and mass spectrometry was used to investigate concentration hysteresis in the low- temperature oxidation of methane over a bimetallic Pt–Pd catalyst. It was shown that a decrease in the oxygen concentration leads to a sharp increase in the catalytic activity of the sample under study. The transition of the catalyst to a high/low activity state occurs due to the partial reduction/oxidation of the active component, with both platinum and palladium participating in the methane oxidation reaction.