Nb_2O_5·nH_2O-PtRu/C的制备及其对甲醇氧化的催化作用  

Preparation and Activity of Nb_2O_5·nH_2O-PtRu/C for Methanol Oxidation

作　　者：李伟伟[1,2] 张向军[1] 卢世刚[1] 

机构地区：[1]北京有色金属研究总院动力电池研究中心,北京100088 [2]新乡学院化学与化工学院,河南新乡453000

出　　处：《化学学报》2012年第9期1073-1080,共8页Acta Chimica Sinica

基　　金：国家高技术研究发展计划(863计划)(No.2007AA03Z245)资助项目~~

摘　　要：采用沉淀法制备了甲醇氧化电催化剂10%Nb2O5 nH2O-20%Pt10%Ru/C,并在Ar气氛下对它进行了热处理.用X射线衍射(XRD),透射电子显微镜(TEM)和X射线光电子谱(XPS)研究了热处理对催化剂的结构和形貌的影响,用循环伏安法和计时电流法研究了热处理对催化剂的电化学性能的影响.结果表明:催化剂中看不到Ru的衍射峰存在,Pt晶粒以面心立方体结构存在,Nb2O5 nH2O对Pt的结合能基本无影响;与20%Pt10%Ru/C相比,同温度热处理的条件下,10%Nb2O5 nH2O-20%Pt10%Ru/C催化剂中Pt,Ru合金化程度较差,活性组分颗粒较小、分散均匀,而且催化甲醇氧化性能和抗"CO"毒化性能较好,700℃热处理的10%Nb2O5 nH2O-20%Pt10%Ru/C的性能最好.Nb2O5 nH2O不仅能抑制热处理过程中活性颗粒的长大和Pt,Ru的合金化,还能促进氢离子的传递,提供活性"-OH",使甲醇及其氧化中间体更容易吸附-脱附.10%Nb2O5·onH2O-20%Pt10%Ru/C electro-catalyst for methanol oxidation was prepared by deposition method, followed with heat treatment in Ar atmosphere. The effect of heat treatment on morphology, structure and electrochemistry performance of the product was characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, X-ray photoelectron spectroscopy （XPS）, cyclic voltammetry and chronoamperograms. No diffraction peaks of Ru were observed in the XRD patterns, while all the peaks of Pt were in accordance with the face centered cubic crystal structure. The binding energy of Pt was not affected by NbEO5.nH2O. Compared with 20%Pt10%Ru/C, in 10%Nb2O5.nH2O-20%Pt10%Ru/C samples, the activated particles were uniformly dispersed, and the performances of methanol oxidation and resistance to ＂CO＂ were better. The results indicated that the introduction of NbEO5.nH2O inhibited the growth of active particles, and decreased the alloying degree of Pt-Ru during heat treatment. Besides, NbEO5onH2O also provided active ＂-OH＂ and improved H＋ transfer, leading to easier adsorption-desorption of methanol and its oxidation intermediates.

关 键 词：热处理 甲醇 Nb2O5-nH2O PTRU/C 

分 类 号：TQ223.121[化学工程—有机化工]