Temperature and Reaction Environment Influence the Nature of Platinum Species Supported on Ceria

Catalytic systems based on supported noble metals are extensively studied because of their widespread application. Discussions remain about the nature active species, whether they atomically dispersed or nanoparticles, and reactivity. In this work, combining in situ/operando spectroscopy with theoretical modeling, we propose a phase diagram platinum ceria, demonstrating that it reversibly changes from PtIVO2 to PtIIO as function temperature oxygen partial pressure. The helps identify stability domain each while spectroscopies provide quantitative evaluation depending reaction conditions. Finally, our results show high-temperature activation presence steam enhances activity toward low-temperature carbon monoxide oxidation promotes aggregation into nanoparticles. This work highlights structure–activity relationship metal catalysts proposes suitable approach determine amount species before investigation mechanism.