Pt monatomic wire supported on graphene nanoribbon for oxygen reduction reaction

B. B. Xiao, X. Y. Lang, Q. Jiang
2014 RSC Advances  
Among the issues inherent to fuel cells, the high cost of the Pt electrocatalyst restricts its widespread application. Controlling nano-or subnano-material structures could improve the utilization of Pt. Here, the catalytic activity of the oxygen reduction reaction (ORR) on Pt monatomic wire that is supported on the zigzag edges of graphene nanoribbon (Pt-GNR) is studied using density functional theory. It is found that Pt-GNR is inert for ORR, due to the strong binding of OH and H 2 O.
more » ... and H 2 O. However, when Pt-GNR is covered by the chain of OH and H 2 O (cPt-GNR), it becomes catalytically active for ORR. Through the free energy diagrams on cPt-GNR, we demonstrate that the highest potential U for ORR as an exothermic process is 0.82 eV. When U is larger than 0.82 V, the rate-determined step (RDS) of ORR is located at the reduction of O 2 * to OOH* (* denotes adsorbed species) where the energy barrier DG is less than 0.41 eV. These results support cPt-GNR as a candidate for ORR. Computational method All calculations are performed within the DFT framework as implemented in DMol3 code. 38, 39 The generalized gradient approximation with the Perdew-Burke-Ernzerhof (PBE) functional is employed to describe exchange and correlation
doi:10.1039/c4ra03387f fatcat:lvl5trjst5ekpht5wdphhlk5oa