| Platinum has been represented as one of the best electrocatalysts in direct methanolfuel cells for its expecptional reactivity. Graphene has attracted wide attention due toits unique properties. Platinum nanoparticles supported on graphene have showedenhanced activity and stability of Pt catalyst for direct methanol fuel cells. It is ofprimordial importance to understand platinum-graphene support interaction and hownanoparticles size affect activity and stability of both catalyst and support.In this article, the interaction between subnano platinum clusters which arecomposed of4-27atoms with pristine graphene (PG), Stone-Wales defect graphene(5775) and monovacancy graphene (VG) has been investigated using the methods ofdensity functional theory (DFT). According to the similar structures of Ptnclustersand eliminating the disruption of different adsorption styles, the subnano platinumclusters all interact with the substrates through one platinum atom. The calculationresults show that the adsorption energy of Ptnclusters interacted with three typesubstrates are all gradually decreased with the size increasing. The adsorptionenergies of Ptnadsorbed on VG are increased significantly compared with thoseadsorbed on PG and5775. The results have been further demonstrated by the partialdensity of states (PDOS), spin density distribution, Mulliken population analysis andelectron density difference of interfacial Pt and C atoms. The analyses results indicatethat the size of Ptnclusters have effects on the interfacial interaction. |
PDF Full Text Request