Mechanism study on CO2 reforming of methane over platinum cluster doped graphene: A DFT calculation

Dry (CO2) reforming of methane is an important reaction in environmental catalysis, which can both reduce the greenhouse gas content and utilize syngas production. Density functional theory (DFT) calculations were carried out to investigate the reaction mechanism of CO2 and CH4 on Pt-4 cluster doped single-vacancy graphene (Pt-4/SV) catalyst. The adsorption configurations are optimized in advance to determine the initial states and final states in reactions. Then, the detailed reaction pathways for CH4 decomposition, CO2 activation, and CH/C oxidation were systematically investigated. In the process of CH4 decomposition, the stage from CH to C+H appears to be the rate-determining step. And the prior reaction pathway of CO2 activation may be CO2*-> CO* + O*. In the process of CH/C oxidation, CH* + O*-> CHO* + *-> CO* + H* and C* + O*-> CO* + * appear to be easier to occur. Finally, thermodynamic and kinetic analysis for CH/C oxidation is carried out to consider the temperature effect and reaction rate. This work gives a deep investigation of the CO2 reforming of methane on Pt-4/SV from the theoretical perspective. It helps to develop the reliable catalyst which has low carbon deposition and high activity.