分析测试学报2011，Vol.30Issue(8)：841-846,852,7.DOI:10.3969/j.issn.1004-4957.2011.08.002
Mg3(VO4)2的环己烷氧化脱氢性能与X射线光电子能谱分析
X-ray Photoelectron Spectroscopy and Catalytic Performance of Mg3 ( VO4 ) 2 Catalyst in Oxidative Dehydrogenation of Cyclohexane
摘要
Abstract
The surface species on Mg3 ( VO4) 2 catalyst prepared by citric acid complexation method,were investigated by X-ray photoelectron spectroscopy (XPS) techniques. In the oxidative dehydro genation of cyclohexane to cyclohexene, the relationship between the catalytic performance over Mg3 (VO4)2 catalyst and the surface species on the catalyst was studied. With the characterization of Xray diffraction (XRD), scanning electron microscopy (SEM), FT - IR spectroscopy ( FT - IR) and H2 -temperature programmed reduction(H2 -TPR) techniques, the results indicated that well crys talline structures of Mg3 ( V04 )2 with a pure phase and a uniform granularity of particles of 110 nm mean size were obtained by the citric acid complexation. XPS spectra also indicated that the lattice oxygen was the main oxygen species among the three oxygen species ( e. G. 0 - , O2- and O2- ) on the catalyst surface. Meanwhile, V4+ and V5+ species were coexisted on the catalyst surface. Although the molar amount of V5 + was a little more than that of V4 + , the isolated VO4 species was the main va nadium species on the catalyst surface owing to the segregation of Mg. In the oxidative dehydrogena tion of cyclohexane, gaseous oxygen participated in the reaction only after adsorption in other parts of the catalyst and then migrated through tne lattice to the active sites by the reoxidation between V4 + and V *. The characterization and the catalytic results also demonstrated that the catalytic performance was correlated to the lattice oxygen O2 ~ and isolated VO4 species, which was beneficial to the improvement of the selectivity to cyclohexene.关键词
Mg3( VO4)2/XPS/环已烷/氧化脱氢Key words
Mg3 ( VO4) 2/ X-ray photoelectron spectroscopy/ cyclohexane/ oxidative dehydrogenation分类
数理科学引用本文复制引用
晋梅,路平,程振民,余国贤..Mg3(VO4)2的环己烷氧化脱氢性能与X射线光电子能谱分析[J].分析测试学报,2011,30(8):841-846,852,7.基金项目
高层次人才科研基金资助项目(2010018) （2010018）
化学工程联合国家重点实验室项目资助(SKL-ChE-08C03) （SKL-ChE-08C03）
