| Summary: | 碩士 === 國立臺灣科技大學 === 化學工程系 === 99 === In this article, we have performed density functional theory (DFT) calculations to investigate CO2 capture and water-gas shift (WGS) reaction over the Ru-Pt/boron-doped graphene surface. The structures and energies of the most important minima and transition states corresponding to the CO2 decomposition and three mechanisms of WGS reaction pathways have been determined based on DFT calculation. From our calculated results, we found that one layer of Ru-Pt/boron-doped graphene nano-sheet, which caused by the substitutive boron defects in graphene model restraining the growth of the metal cluster, has lower the production costs and excellent catalyst compared with the pure Pt(111) surface. The adsorption energy of CO2 molecule on the Ru-Pt/boron-doped graphene surface is quite large, -0.76 eV, which is higher than the further decomposition barrier, 0.63 eV. It indicates that Ru-Pt/boron-doped graphene surface, due to the intrinsic high surface areas and polarity, is a good catalyst for CO2 capture and also has high activity for CO2 decomposition. Predicting from our results, three mechanisms of WGS reaction on Ru-Pt/boron-doped graphene surface, redox, carboxyl and formate mechanisms can happen. The rate-determining steps for both redox and carboxyl mechanisms are CO2 desorption, and the reaction barrier of this step is 0.69 eV on Ru-Pt/boron-doped graphene surface. However, the rate-determining steps for formate mechanisms is relatively higher, 1.00 eV, compare with the other mechanisms.
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