PEMFC膜电极电催化层的制备和性能

膜电极催化层的组成和电催化剂的活性对质子交换膜燃料电池的性能有很大影响．采用浸渍还原法制备出了Pt平均粒径为3．1nm的Pt／C催化剂．催化剂中Pt的粒径和在碳黑载体（VulcanXC-72）表面的分散程度采用透射电镜（TEM）进行测试．用Pt／C催化剂、适量的Nation溶液和PrFE乳液制备出质子交换膜燃料电池（PEMFc）膜电极的催化剂层，并研究了该催化剂层中PTFE含量对其性能的影响．实验表明，PTFE强烈的疏水性可以迫使部分水分向阳极反扩散，催化层中加入适量的PTFE可以使膜电极具有一定的水管理能力，在去掉辅助增湿系统的条件下具有良好的极化性能．

Preparation and Performance of Electrocatalytic Layer of Membrane Electrode Assemblies in PEMFC

The performance of a proton exchange membrane fuel cells(PEMFC) is substantially influenced by the electroactivity of catalyst and composition of catalyst layer in the membrane electrode assembly(MEA).Pt/C catalyst with 3.1 nm platinum crystals was prepared using impregnation-reduction method. and the particle size and the degree of dispersion of Pt on the carbon black support(Vulcan XC-72) were observed by transmission electron microscopy(TEM).The catalyst layer of prepared MEA consisted of Pt/C catalyst, Nafion solution and PTFE emulsion. The effect of PTFE content on the performance of membrane electrode assembly (MEA) was investigated. The results demonstrated that the MEA wtih a suitable amount of PTFE in catalyst layer had a certain ability of water management because the strong hydrophobicity of PTFE enhanced the diffusion of reaction water towards anode, and therefore, the excellent polarization performance of a PEMFC with dry reactant gases was achieved.