摘要
采用离子束溅射镀膜技术(IBS)制备Pt Cu-Ce Ox复合薄膜电极,并对膜电极进行不同温度的酸蚀处理。分析酸蚀处理温度对膜电极性能的影响,并进一步讨论薄膜表面组分、结构与催化性能的相关性。X射线衍射(XRD)和带能谱的扫描电子显微镜(SEM-EDS)结果表明,Cu掺杂和酸蚀去合金化处理均降低了Pt的晶面间距,这有助于提高Pt的电子云密度,提高膜电极的催化性能;Ce Ox的加入增强了Pt颗粒的分散度,降低Pt(111)的表面能,促进Pt(111)的择优生长;膜电极催化性能与其活性比表面积之间呈现非正比关系,相对于比表面积,表面催化主相Pt的相对浓度的影响更为重要;电化学测试结果表明,经过300℃的1 h真空热处理以及在30℃、0.5 mol·L-1的H2SO4溶液中酸蚀处理30 min后的试样,析氢活性比原样提高6.78%,电感耦合等离子体发射光谱仪(ICP-AES)数据显示,其Pt载量仅为0.115 mg·cm-2,表现出低Pt耗量高催化性能的明显特性。
PtCu-CeOx composite membrane electrodes were prepared by ion beam sputtering deposition technology （IBS）, and were treated by acid etching under different acid temperatures. The impacts of acid etching temperature on the properties of membrane elec- trodes were analyzed, and further the correlation of thin film surface composition, structure and catalytic performance was discussed. The X-ray diffraction （XRD） and scanning electron microscopy equipped with energy dispersive spectrometer （SEM-EDS） results showed that, after Cu doped and acid treated, the decrease of crystal face space of Pt could improve the density of electrons and catalyt- ic performance of membrane electrodes. The addition of CeOx could enhance the dispersion of Pt particles, reduce the face space of Pt （ 111 ） and promote preferential growth of Pt （ 111 ）. The catalytic properties of membrane electrode and its active specific surface area presented the non-proportional relationship, and compared with specific surface area, the influence of relative concentrations of main cata- lytic phase Pt was more important. Electrochemical test results showed that through vacuum heat treatment of 300 ℃ for 1 h and H2SO4 concentration of 0.5 mol·L^-1 with acid solution treatment for 30 min, the hydrogen-evolution activity was higher than that of original sample by 6.78%, and inductively coupled plasma-atomic emission spectrometry （ICP-AES） data showed that the Pt loading was only 0.115 mg·cm^-2, which demonstrated obvious characteristics of low Pt consumption hut high catalytic performance.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2015年第5期435-441,共7页
Chinese Journal of Rare Metals
基金
国家自然科学基金项目(51261012)
昆明理工大学分析测试基金项目(20130107
20130040)
昆明理工大学"泡沫金属创新团队"项目(2010-06)资助
