CO oxidation catalyzed by Pt-embedded graphene: A first-principles investigation
KAUST DepartmentAdvanced Membranes and Porous Materials Research Center
Physical Sciences and Engineering (PSE) Division
Chemical Science Program
Nanostructured Functional Materials (NFM) laboratory
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AbstractWe addressed the potential catalytic role of Pt-embedded graphene in CO oxidation by first-principles-based calculations. We showed that the combination of highly reactive Pt atoms and defects over graphene makes the Pt-embedded graphene a superior mono-dispersed atomic catalyst for CO oxidation. The binding energy of a single Pt atom onto monovacancy defects is up to -7.10 eV, which not only ensures the high stability of the embedded Pt atom, but also vigorously excludes the possibility of diffusion and aggregation of embedded Pt atoms. This strong interfacial interaction also tunes the energy level of Pt-d states for the activation of O2, and promotes the formation and dissociation of the peroxide-like intermediate. The catalytic cycle of CO oxidation is initiated through the Langmuir-Hinshelwood mechanism, with the formation of a peroxide-like intermediate by the coadsorbed CO and O2, by the dissociation of which the CO2 molecule and an adsorbed O atom are formed. Then, another gaseous CO will react with the remnant O atom and make the embedded Pt atom available for the subsequent reaction. The calculated energy barriers for the formation and dissociation of the peroxide-like intermediate are as low as 0.33 and 0.15 eV, respectively, while that for the regeneration of the embedded Pt atom is 0.46 eV, indicating the potential high catalytic performance of Pt-embedded graphene for low temperature CO oxidation.
SponsorsThis work was supported by NSFC (21373036, 21103015, 21271037 and 11174045), the Fundamental Research Funds for the Central Universities (DUT14LK09 and DUT12LK14), the Key Laboratory of Coastal Zone Environmental Processes YICCAS (201203), the Key Science and Technology International Co-operation Foundation of Hainan Province, China (KJHZ2014-08) and the Special Academic Partner GCR Program from King Abdullah University of Science and Technology. Y.H. would also thank Dalian University of Technology for the Seasky Professorship.
PublisherRoyal Society of Chemistry (RSC)
JournalPhys. Chem. Chem. Phys.