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Pt
A 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.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
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
