Preparation Of Pt Based Nanomaterials And Their Applications In Fuel Cells

Green energies have become a key factor in the sustainable development of social economy,among which DMFC(Direct methanol fuel cell)is a new energy source with promising future.Development of anode catalyst with superior performance is very important for the improvement of DMFCs.As a main DMFC anode catalyst,Pt based catalyst has attracted a great deal of interest to improve its activity and reduce its cost.CO poisoning is the main factor leading to the decreased performance of DMFCs anode catalyst and needs to be overcome before the commercialization of DMFCs.Moreover,solar energy is considered to be a clean and economical energy source with unmatched resource potential.Significant researches have been focused on using solar energy to improve catalyst performance.In this paper,two kinds of nanomaterials were developed for methanol electro-oxidation and photoelectrochemical oxidation of methanol,respectively.The full paper includes the following two points.Firstly,Pt/FeSnO(OH)5,Pt/CoSn(OH)6 and Pt/ZnSn(OH)6 hollow nanocubes were designed and synthesized as anode catalysts for DMFC.Stannate hydroxide is a class of perovskite-structured hydroxide with a large number of hydroxyl groups on the surface,which is benefitful for catalysts to improve the performance towards methanol oxidation reaction.Herein,we synthesized a series of stannate hydroxides including FeSnO(OH)5,CoSn(OH)6 and ZnSn(OH)6 nanocubes by a favile co-precipitation method,which became hollow by a etching route,and then Pt/FeSnO(OH)5,Pt/CoSn(OH)6 and Pt/ZnSn(OH)6 hollow nanocubes were fabricated using Vitamin C as a reductant.Compared to Pt/C,the stannate hydroxide supported Pt catalysts exhibited higher mass activity towards methanol oxidation,better stability,lower charge transfer resistances and increased resistance of CO poisoning,among which,the catalytic performance of Pt/FeSnO(OH)5 is the best.Clearly,the stannate hydroxides have great application prospect as high-performance electrocatalyst supports for methanol electrooxidation in DMFC.Secondly,a straightforward and green synthetic strategy was employed for NiPt alloy nanoparticles using tannic acid,a kind of plant polyphenols,as assisted agent.The as-prepared NiPt alloy nanoparticles showed good photothermal performances and displayed a longitudinal light-absorption in the ultraviolet region and the visible region.Under irradiation,the mass activity of NiPt alloy was improved significantly,better than pure Pt,which was increasing with the rising illumination intensity.When the same methanol oxidation current density was achiebved,the stability of the NiPt alloy under irradiation was better than that of the NiPt alloy in high temperature solution.Therefore,the NiPt alloy nanoparticles can act as a promising candidate for the photo-electrocatalyst in direct methanol fuel cells.