Mo-V-O复合金属氧化物的制备及其分子氧氧化苯甲醇反应的催化性能

PREPARATION OF Mo-V-O COMPOSITE METAL OXIDES AND THE CATALITIC PERFORMANCE OF MOLECULAR OXYGEN IN OXIDATION OF BENZYL ALCOHOL

采用亚临界水制备Mo-V-O复合金属氧化物,考察制备条件对其结构及催化苯甲醇氧化反应性能的影响。运用X射线衍射、N2吸附-脱附、场发射扫描电子显微镜、H2程序升温还原、NH3程序升温脱附等手段对Mo-V-O复合金属氧化物的相组成、形貌及其表面性质进行了表征。结果显示,Mo-V-O复合金属氧化物由大量的Mo0.97V0.95O5相与少量的VO2和V2MoO8相组成,且呈现出由片状晶体堆叠而成的板状颗粒形貌。苯甲醇氧化反应结果表明:Mo-V-O复合金属氧化物制备条件对其性能有显著影响,制备温度为420℃、制备压力为19 MPa时得到的Mo-V-O复合金属氧化物催化苯甲醇氧化性能最优,在90℃、反应6 h条件下催化苯甲醇氧化为苯甲酸的转化率为5.35%,选择性为76.43%,收率为4.09%。

Mo-V-O composite metal oxides were prepared by subcritical water.The phase composition,morphology and surface properties of Mo-V-O composite metal oxides were characterized by means of X-ray diffraction,N2 adsorption-desorption,field emission scanning electron microscope,H2 temperature-programmed reduction and NH3 temperature-programmed desorption.The results show that Mo-V-O composite metal oxides consist of a large number of Mo0.97V0.95O5 phase and a small number of VO2 and V2MoO8 phase.The samples present plate-like morphologies by the stacking of flake crystals.The catalysis result shows that the preparation condition of Mo-V-O composite metal oxides has a significant effect on the performance.The sample as-prepared under preparation temperature 420℃and pressure 19 MPa exhibits the maximum benzyl alcohol conversion rate,selectivity and yield of benzoic acid of 5.35%,76.43%,and 4.09%,respectively.