摘要
以CeO2为载体和钼酸铵为原料,在70℃下,采用水热法制备了MoO3含量分别为0、5wt%、7.5wt%、10wt%、12.5wt%、15wt%和20wt%的杂化型MoO3/CeO2复合催化剂.采用X射线粉末衍射(XRD)、傅立叶变换红外光谱(FT-IR)、X射线光电子能谱(XPS)、扫描电镜(SEM)和X射线能谱仪(EDS)等对所制备催化剂的结构、形貌以及表层MoO3与CeO2之间的相互作用进行分析;并以硫酸溶液水电解为目标反应,对杂化材料进行了电催化活性测试,考察MoO3含量对复合催化剂反应活性的影响.结果表明,杂化型MoO3/CeO2催化剂的电催化活性明显优于纯CeO2,当MoO3的质量含量为12.5wt%时,所制备复合催化剂的电催化活性和导电性较佳.活性提高的主要原因是MoO3在CeO2表面上的单层分散阈值在12.5wt%～15wt%之间,MoO3通过Mo O Ce化学键而牢固结合在CeO2表面,改善了杂化型MoO3/CeO2复合催化剂的表面性能.
A series of molybdic oxide/ceria （MoO3/CeO2） composite catalysts with different MoO3 concentrations （0, 5wt%, 7.5wt%, 10wt%, 12.5wt%, 15wt% and 20wt%） were prepared by hydrolysis of ammonium mo- lybdate and the supports of CeO2 at 70℃. The crystal structure, the morphology and interaction between MoO3 and CeO2 on the surface of the prepared MoO3/CeO2 composite catalysts were characterized by X-ray diffraction （XRD）, Fourier transform infrared spectroscope （FT-IR）, X-ray photoelectron spectrometer （XPS）, scanning electron microscope （SEM） and energy dispersive spectrometer （EDS）, respectively. The catalytic activities of the prepared catalysts were evaluated by the electrolysis sulfuric acid solution. Results show that the catalytic activity of MoO3/Ce02 composite catalysts are superior compared with that of pure Ce02, and the optimal concentration of MoO3 is 12.5wt%. The MoO3 content threshold value of composite catalysts is between 12.5wt% and 15wt%, and it is identified that the Mo-O-Ce bond forms at the interface of MoO3 and CeO2 in the compos-ite catalysts. Moreover, more surface Mo-O-Ce bond over the MoO3/Ce02 composite catalysts will further benefit the improvement of the catalytic activity.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2012年第9期939-944,共6页
Journal of Inorganic Materials
基金
国家自然科学基金(50974065
51004057)
云南省应用基础研究计划(2011FZ031)
昆明理工大学分析测试基金(2010022)~~
关键词
水热法
三氧化钼
二氧化铈
杂化
催化活性
hydrothermal molybdic oxide ceria composite catalytic activity
