PEMFC催化剂的研究:自制抗CO中毒Pt-Ru/C电催化剂的性质  

Study of PEMFC Electro-Catalysts: Characteristics of a Homemade CO-Tolerant Pt-Ru/C Catalyst

作　　者：李莉[1] 王恒秀[1] 徐柏庆[1] 李晋鲁[1] 陆天虹[2] 毛宗强[3] 

机构地区：[1]清华大学化学系一碳化学与化工国家重点实验室,北京100084 [2]中国科学院长春应用化学研究所,长春130022 [3]清华大学核能技术设计研究院,北京100084

出　　处：《化学学报》2003年第6期818-823,共6页Acta Chimica Sinica

基　　金：国家重点基础研究发展规划项目 (No .G2 0 0 0 0 2 640 8);教育部"优秀跨世纪人才"基金;清华大学分析测试基金资助课题

摘　　要：用胶体法制备了抗CO中毒PEMFC阳极Pt Ru/C电催化剂 (标记为THYT 2 ) ,对比研究了THYT 2与JohnsonMatthey(JM)公司同类品牌Pt Ru/C催化剂的电化学及其它物理化学性能 .结果表明 ,THYT 2电催化剂在甲醇燃料电池和CO/H2(ΦCO=1× 10 -4)的氢氧燃料电池中的电催化行为与JM催化剂相当 ,但THYT 2在低浓度CO氢气燃料中的电池性能更好 .两种催化剂的其它物理化学性质具有类似性 :XPS分析结果表明THYT 2和JM催化剂中都有三种不同价态的Pt存在 :即金属态Pt(0 )、氧化态Pt(II)和Pt(IV) .HRTEM测试结果表明两种催化剂的粒径处在 2～ 3nm左右 ,这可能是它们拥有良好电化学性能的主要原因之一 .本文还对催化剂中Pt与Ru组分的分布和相互作用进行了讨论 ,提出了改进PtA homemade Pt-Ru/C catalyst (named THYT-2) was characterized and used as CO-tolerant electrocatalyst for the proton-exchange membrane fuel cell (PEMFC). While THYT-2 showed comparable electrocatalytic activity with that of the commercial Pt-Ru/C catalyst (Johnson Matthey Corporation) by the single-cell performance with CO/H-2(Phi(CO) = 1 x 10(-4)) or methanol as the fuel, higher resistance toward CO-poisoning was demonstrated when the CO-concentration in the hydrogen fuel was reduced to 1 x 10(-5). The electrochemical oxidation of CO on THYT-2 and the Johnson Matthey Pt-Ru/C catalysts was also indistinguishable by the results of CO-stripping experiment. XRD and XPS measurements show that 60% of the platinum in both catalysts existed in the metallic state of Pt(0) and the other 40% in oxidized Pt(II) and Pt(IV) states. High-resolution TEM detection demonstrates uniformly dispersed Pt-Ru crystals with sizes of 2 similar to 3 nm of both catalysts, but selected area EDX analysis reveals non-uniform distribution of ruthenium in the Pt-Ru nano-crystals, which suggest that further improvement of the electrocatalyst can be made with deliberate control of the distribution and interaction of the two metal components.

关 键 词：PEMFC催化剂 抗CO中毒 Pt-Ru/C电催化剂 性质 胶体法 碳负载铂铑催化剂 质子交换膜燃料电池 一氧化碳中毒 

分 类 号：O643.3[理学—物理化学]