Preparation Of PTSN/G-CNT Catalyst And Its Performance On Catalytic Oxidation Of Ethanol

Direct ethanol fuel cells(DEFCs),as a promising alternative power source for portable electronic devices,have attracted wide attention due to the high energy density,low pollutant emission,abundant fuel sour and renewable in recent years.As the core component of the fuel cell,the catalyst has a direct impact on the performance of the fuel cell.Metal Pt exhibited high catalytic activity in the catalytic oxidation of ethanol,however,the serous adsorption poison of CO-like on Pt and the high cost of noble-metal have hampered the commercialization of such cells.Generally,it is believed that the introduction of the outer metals to form Pt-based catalysts can effectively solve the poisoning problem of the catalysts.The PtSn bimetallic catalyst has shown good catalytic performance,and the load of PtSn has an important influence on the performance of the catalyst.In addition,the appropriate catalyst support material can effectively improve the electrochemical performance of the catalyst.In this study,a series of PtSn bimetallic catalysts were prepared by impregnation reduction method based on the important influence of metal load and the carrier materials on the performance of the catalyst.The synthesized catalysts were applied to the DEECs anode catalyst experiment,and the electrochemical performance of catalysts for ethanol oxidation has been studied.The main contents and conclusions are summarized up following two parts.1?First,graphene oxide was synthesized by improved Hummers method.Then,under fixed atomic ratio of Pt and Sn,PtSn/graphene catalysts with metal theoretical loading of 20%,30%and 40%(mass fraction)were prepared using polyol method with graphene as carrier.The results show that the metal load affects the catalytic oxidation performance of the catalyst by affecting the distribution and particle size of the active component of the catalysts.The PtSn/graphene catalyst with load of 30%has the highest catalytic and good stability for ethanol oxidation.The average particle size of metal particles for this catalyst is 2.67nm,and the current density for ethanol oxidation is 407.03mA mg-1.2.G-CNT composites with three-dimensional space structure were prepared by assembling of carbon nanotubes and graphene.And PtSn/G-CNT catalysts were successfully synthesized using the impregnation-reduction method with G-CNT composites as carrier.The size and dispersion of the PtSn nanoparticles on catalysts were tuned by adjusting the ratio of graphene and carbon nanotubes in the G-CNT composites.The present work indicated that the PtSn/G-CNT catalysts with narrower size and more uniform distribution exhibited ultrahigh electrocatalytic activity and stability for ethanol oxidation.PtSn/G-CNT catalyst has the highest catalytic activity and stability for ethanol oxidation when the mass ratio of graphene and carbon nanotube in G-CNT composites is 2:1.The average particle size of metal particles for this catalyst is 2.09 nm,and the current density for ethanol oxidation is 741.52 mA mg-1.