(330g) A First-Principles Study On Carbon Dioxide Reforming of Methane Over Supported Pt Catalysts

Synthesis of fuels and chemicals via dry reforming of carbon dioxide and methane, which are both greenhouse gases, has the vast potential for closing the carbon cycle and providing clean energy. For this reason, much effort has been dedicated to exploring efficient ways for the reduction of CO₂ and the dehydrogenation of CH₄ into small building block for use in syngas chemistry. Pt/Silica and Pt/Ceria are promising catalysts for dry reforming due to the reactivity at the metal-support interface. In this study, we use first-principles density functional theory and Kinetic Monte Carlo method to investigate the details of the adsorption and reaction process on these two supported catalyst systems. We found that CO₂ prefers to be adsorbed, with OCO angle of 136.9^◦, onto reduced Ceria (110) to form the active carbonate unit [(CO₃)^2-] as the first step in CO₂ reduction, while CH₄ prefers to dehydrogenate via Pt nanoclusters.  Also, we found that the shape of Pt cluster is vitally important in controlling catalytic activity, and the use of faceted catalyst particles opens up possibilities for low-temperature and energy-efficient hydrocarbon transformations. We map the dry reforming pathway by identifying the reaction intermediates and transition states, and calculating the energy barriers. The results obtained advance our fundamental understanding of the dry reforming mechanisms, and provide a design strategy for the simultaneous reduction of CO₂ andthe dehydrogenation of CH₄ on supported Pt catalysts.