Preparation And Performance Research Of Multi-component&Low Pt Loading Catalysts For Fuel Cells

The energy is the vital material base on which then human society relies forsurvival and development. At present, non-renewable energy resources such as coal andoil are one of the most important energy resources, which are widely used in our dailylife and industrial production. But they are non-renewable resources and earth storagecapacity is limited. While traditional heat engines convert chemical energy to heat,electricity and other energy, their efficiency is fundamentally limited by the Carnot’stheorem. Therefore, the energy utilization ratio is low, and the environment isseriously polluted. Fuel cells have a wide range of advantages such as high energyconversion efficiency and wide application. They are also environmentally friendly andavailable with variety of fuels, which are much concerned day by day in the process oflooking for new energy technologies.Currently, commercial Pt catalyst is the most wide used catalyst in fuel cells.However, Pt catalyst has some main problems.(a) The high cost of clothes and resourcescarcity bring the high cost of fuel cells. Therefore, lowering the costs without loss ofthe performance is still the obstacle for the commercialization of fuel cells.(b) Somepoisonous intermediates such as CO will be generated and strongly adsorbed on catalystsurface in the process of ethanol electro-oxidation, blocking the surface active sitesfrom further catalysis. So we change the structure and component of the catalysts to gethigher catalytic activity and stability.(c) Develop reasonable preparation method ofcatalysts to reduce cost and synthesis ideal catalyst. The main problems are theobstacles for the commercialization of fuel cells.Based on the above consideration, in this thesis, we design a facile route for thelarge-scale synthesis of low-Pt and stable TePtPd catalysts by using Te nanoribbons asboth sacrificial templates and reducing agents, which have special structures. Low thecosts without loss of the catalytic activity and stability by fine-tuning of thecompositions and material structures. Meanwhile we discusses the application prospectsof the catalysts. The details are as follows:(1) Firstly, we presented a controlled hydrothermal route to synthesize unique Tenanoribbons, which have1D tri-wing and2D nanobelt structures. Futhermore, theywere used as both sacrificial templates and reducing agents. We synthesized TePtPdnanomaterial that have tri-wing and strip structure by Galvanic replacement, as the same time, the TePtPd nanoribbons can remain the structure as well as the sacrificialtemplates(2)We discussed the effect of the different tri-wing catalysts, including thedifferent-component(two-component Te53Pt47and three-component Te62Pt11Pd27)tri-wing catalysts and different elemental content (Te53Pt10Pd33, Te62Pt11Pd27andTe62Pt20Pd18)on catalytic properties and stability for fuel cells. The electrochemicalperformance tests show that Te62Pt11Pd27exhibit the highest eletrocatalytic activity, andthe stable active surface area is1.5times higher than that of commercial Pt/C catalysts.(3)In the process of synthesis of the unique catalyst, we systhesized two kinds ofcatalysts:1D tri-wing and2D nanobelt structure, and research on the effect of thestructure on eletrocatalytic activity and stability for ethanol electro-oxidation. Differentstructures exhibit different eletrocatalytic activity. The tri-wing TePtPd nanomaterialsshow higher eletrocatalytic activity, compared with the strip nanobelts.