Study On The Application Of Gold Catalyst In PEMFC Electrocatalysts

Electrocatalyst is one of key materials of proton exchange membrane fuel cells (PEMFCs). At present, the cost of the electrocatalysts used in PEMFCs is very high, which is one of the obstacles for the commercialization of PEMFCs. The gold catalyst is promising to be the electrocatalyst for PEMFCs, because of its especial catalytic activity and relative lower price. The aims of this thesis are to study the application of gold catalyst in PEMFCs electrocatalyst, to prepare good CO-tolerant anode electrocatalyst and oxygen reduction cathode electrocatalyst which contain the active component gold. The works can improve the performance of fuel cell, which have practical meanings for developing the PEMFCs.Firstly, a series of PtAuFe/C catalysts were prepared via a microwave-irradiated polyol plus annealing (MIPA) synthesis strategy, and both the synthesis route and the content of Fe and Au in the catalysts were investigated. The single cell tests and the gas chromatography analyses revealed that the PtAuFe/C catalysts were promising as CO-tolerant anode electro-catalysts for PEMFCs application. On the basis of the results of both the CO stripping voltammetry measurements and the gas chromatography analyses, the mechanism for the enhanced performance of the PtAuFe/C catalysts was preliminarily explored.Secondly, The PtAuFe/C and PtAuNi/C catalysts as CO-tolerant anodeelectro-catalysts were compared with the commercial PtRu/C catalyst, and were characterized by XRD, CO-stripping voltammetry, single cell tests, and gas chromatography analyses, etc. The works proved that the mechanism for the enhanced performance of the PtAuFe/C and PtAuNi/C catalysts was gained by the low temperature water gas shift reaction in the electrode, which was different from the bifunctional mechanism of PtRu/C catalyst.In addition, a series of PtMAu/C (M=Fe, Zr, Ni) for oxygen reduction in cathode were prepared, and they were characterized by XRD, CV, RDE and single cell test. These catalysts not only showed high activity for oxygen reduction reaction, but also reduced Pt loading in the catalysts and lowered the price of PEMFCs electrocatalyst.