Study On The Electronic Structure Of Pt Cluster And Their Oxidation Reduction Reaction

With the continuous consumption of fossil fuels, energy crisis is worsening. People need an efficient and clean energy conversion technologies. On this basis, more and more people pay attention to the fuel cell. The fuel cell can convert chemical energy directly into electricity without the need to go through the combustion stage, it is a clean and efficient energy equipment, which is very promising in the field of vehicles,portable devices and distributed power plants. Wherein the battery energy proton exchange membrane (PEMFC) is one of the most clean and efficient fuel cell type. However,the high cost of PEMFC electrode material and bad stability are two reasons hindering its commercial. Therefore, it is very important to find a kind of catalyst with low cost and good stability.In this paper,the electronic structure and physical structure of M13Pt42(M = Al, Ga, In, Mg, Ca, Sr) are studied in detail by using the first-principles calculation method. Our calculations show that Mg13Pt42,Al13Pt42, Ga13Pt42 acted as oxygen reduction reaction (ORR) catalysts is stable while considering both the core-shell interaction energy (Ecs) and the potential energy (Udiss). By analyzing the Partial Density of State(PDOS), we find that it is more favorable to form p-d hybridization than to form d-d hybridization when p-block element cores interact with Pt shell.The absorption energies of O atom show that the adsorption energy of surface is closely related to the charge that the surface gains.Secondly, the adsorption mechanism and redox mechanism of M13Pt42(M = Al, Ga, In) surface were studied based on the previous research. The results show that the adsorption of small molecules on Pt (111) surface is stronger than that of M13Pt42; For M13Pt42, the adsorption energy of Ga13Pt42 is the weakest; The adsorption energy of In13Pt42 is stronger than that of Al13Pt42. In addition, the most stable positions of O, O2 and OH adsorbed on Pt (111) and In13Pt42 are different from the most stable positions of Al13Pt42 and Ga13Pt42. The cause of this difference may be the surface tension effect. The energy barrier of M13Pt42 (M = Al, Ga, In)clusters is lower than that of M13Pt42 (M = Al, Ga, In), which is more favorable for oxidation reduction reaction. For Pt (111), the energy barrier of the O2-generated OOH mechanism is lower and more prone to occur.The energy barrier of M13Pt42 on the O2 decomposition mechanism is about 0.55, which is much lower than that of Pt (111) 0.91eV.Finally, Al13Pt42 and Ga13Pt42 are promising catalysts,based on the results of structural properties and reaction simulation.