载体炭与Pt催化剂之间的相互作用及其引起的尺寸效应(英文)  

The effect of particle size on the interaction of Pt catalyst particles with a carbon black support

作　　者：干林[1,2] 杜鸿达[1,2] 李宝华[2] 康飞宇[1] 

机构地区：[1]清华大学材料科学与工程系先进材料教育部重点实验室,北京100084 [2]清华大学深圳研究生院新材料研究所,深圳518055

出　　处：《新型炭材料》2010年第1期53-59,共7页New Carbon Materials

基　　金：National Nature Science Foundation of China (50632040 and 50902079);fundamental research program of Shenzhen(Jc200903180520A)~~

摘　　要：通过乙二醇还原,在VulcanXC-72炭黑上负载了三种具有不同平均粒径(1.7nm,3.0nm和5.0nm)的Pt催化剂。利用透射电子显微镜,研究了载体炭黑表面的微孔与Pt催化剂之间的几何相互作用。结果表明:尺寸较小的Pt颗粒(平均粒径为1.7nm)通常被包含在载体表面的微孔中,表现为被一薄碳层所覆盖并嵌入炭黑基体。而尺寸较大的Pt颗粒(平均粒径为3.0nm和5.0nm)则不存在这种现象,往往显示出裸露的清洁表面。这种与载体表面微孔的不同相互作用引起了Pt颗粒在电化学活性比表面上的反常尺寸效应,进而影响了其催化甲醇氧化的质量比活性。Pt catalysts with different average particle sizes （1.7,3.0,and 5.0 nm） were supported on Vulcan XC-72 carbon black through ethylene glycol reduction of H2PtCl6. Using transmission electron microscopy,we found a geometric interaction between the micropores on the surface of carbon black support and the supported Pt catalysts. Small Pt nanoparticles （with an average particle size of 1.7 nm） were found to be frequently incorporated into the micropores,and thus appeared to be covered by a thin carbon layer and embedded in the carbon matrix. However,such a phenomenon was Absent for Pt particles with larger average particle sizes （3.0 and 5.0 nm）,which generally showed an exposed clean surface. The different interaction with the micropores therefore induced an abnormal particle size effect of the supported Pt catalysts on their electrochemically active surface area,and had an influence on their mass electrocatalytic activity towards methanol oxidation.

关 键 词：催化剂 甲醇氧化 尺寸效应 金属-载体相互作用 透射电子显微镜 

分 类 号：O643.36[理学—物理化学]