Preparation And Properties Of Carbon Nanotubes Supported Low-platinum Catalysts

The shortage of energy and the environment pollution has a serious impact on modern life in the past few decades,it is imperative to seek and develop a new energy source.Fuel cell technology is environmentally friendly,widely used and has high energy conversion rates considered to be the most promising solution.The role of the catalyst in the fuel cell system is indispensable,so the selection of the catalyst is particularly important.Commercial catalysts are generally noble metal platinum,and the price of metal platinum is relatively expensive and limited availability,making the further commercialization of the catalyst subject to certain constraints.Therefore,reducing the use of platinum and prolong its life to promote the development of fuel cells play an important role.This article,carbon nanotubes as a carrier supported platinum catalyst,and the optimum diameter of carbon nanotubes was selected as the carrier to prepare the platinum-nickel alloy catalyst.The prepared catalyst was studied by a series of structural characterization and electrochemical test.The prepared catalysts were studied by a series of structural cnaractenzation and electrochemical tests.The research contents are listed as follows:(1)A series of modified carbon nanotubes(CNT)(8-15,20-30,30-50,and>50 nm)were selected as catalyst carriers,and CNT loaded platinum(Pt)catalyst(Pt/CNT)were prepared by microwave-assisted ethylene glycol.The effects of different diameters on the comprehensive performance of the catalysts were investigated by structural characterization and performance testing.The best performance carbon nanotubes were obtained as the catalyst carriers by comparison with commercial JM Pt/C.When diameter of CNT was 8-15 nm,the best comprehensive performance of the catalyst,compared to JM Pt/C catalyst performance has greatly improved.(2)The platinum-nickel alloy catalyst(PtNi/CNT)was prepared by microwave method using the best diameter carbon nanotubes as the carrier.The effects of different N,N-dimethylformamide(DMF)additions and different platinum-nickel atomic ratios on the structure,electrocatalytic performance and stability of the catalysts were investigated and compared with commercial JM Pt/C.When the DMF added in the solvent was 10 mL and the platinum-nickel atom was 1:3,the quality activity of PtNi/CNT catalyst was 0.168 A·mg-1pt,which was twice as much as JM Pt/C catalyst,and the stability improved.(3)Polyaniline supported on the surface of carbon nanotubes(PANI/CNT)by in situ growth method as a carrier for preparing platinum nickel alloy catalyst(PtNi/PANI-CNT)by microwave method.The effects of the content of polyaniline on the morphology of the supported and metal particles were investigated.In addition,the effects of different Pt/Ni atomic ratios on the catalyst structure,electrocatalytic performance and stability were investigated,and compare with commercial JM Pt/C.Results show that when the aniline and CNT atomic ratio of 1:1,platinum-nickel atoms ratio of 1:1.5,the quality of the catalyst activity is 0.532 A·mg-1 Pt,indicated that the introduction of PANI can greatly improve the catalyst activity and stability.