化学学报 ›› 2006, Vol. 64 ›› Issue (5): 409-414. 上一篇    下一篇

研究论文

Cu/NiO-V2O5/SiO2催化剂光催化CO2和甲醇合成碳酸二甲酯的研究

孔令丽,钟顺和*,柳荫,肖秀芬   

  1. (天津大学化工学院 天津 300072)
  • 投稿日期:2005-04-30 修回日期:2005-11-14 发布日期:2006-03-15
  • 通讯作者: 钟顺和

Study on Photo-catalytic Synthesis of Dimethyl Carbonate from CO2 and CH3OH over Cu/NiO-V2O5/SiO2 Catalyst

KONG Ling-Li, ZHONG Shun-He*, LIU Yin, XIAO Xiu-Fen   

  1. (College of Chemical Engineering and Technology, Tianjin University, Tianjin 300072)
  • Received:2005-04-30 Revised:2005-11-14 Published:2006-03-15
  • Contact: ZHONG Shun-He

采用表面改性法和等体积浸渍法制备了NiO-V2O5/SiO2和Cu/NiO-V2O5/SiO2光催化剂. 用TPR, XRD, UV-Vis DRS, IR和TPD-MS技术对催化剂的结构、吸光性能和化学吸附性能进行了表征, 研究了催化剂上CO2和甲醇光促表面催化反应的反应性能. 结果表明, 半导体NiO和V2O5复合后部分形成了Ni2+—O—V5+键联, 而且NiO和V2O5在催化剂表面有相互修饰作用, NiO的加入有助于提高V2O5在载体SiO2表面的分散程度, 抑制V2O5的聚集, 而且金属Cu和NiO的引入扩展了催化剂的光响应范围. 在催化剂表面存在多种活性吸附位, 催化剂对CO2和甲醇的有效吸附使得其在较低温度下就能促进碳酸二甲酯的紫外光化学合成. 用Cu/NiO-V2O5/SiO2催化剂, 在常压、空速300 h-1、140 ℃和125 W紫外灯辐照的情况下, CH3OH的转化率为14.2%, 碳酸二甲酯的选择性可达89.9 %.

关键词: 光催化, 复合半导体, 二氧化碳, 甲醇, 碳酸二甲酯

NiO-V2O5/SiO2 and Cu/NiO-V2O5/SiO2 were prepared by surface reaction modification method and isometric impregnation method, on which photo-stimulated surface reaction ability of synthesis of dimethyl carbonate (DMC) from CO2 and CH3OH were studied. TPR, XRD, UV-Vis DRS, IR and TPD-MS techniques were used to study the structure, light adsorption ability and chemisorption abilities of such catalysts. The results showed that Ni2+—O—V5+ bond was formed on the surface of catalyst after NiO and V2O5 were coupled, and NiO and V2O5 on the surface of support could act with each other. NiO promoted the dispersion of V2O5 on the surface of silica, which effectively prevents V2O5 from aggregation, and the addition of Cu and NiO could expand the light-responding scope of photo catalyst. There were multiple active adsorption sites on the surface of catalyst, and the effective chemisorptions of CO2 and methanol on the catalyst greatly promoted the photochemical synthesis of DMC even at lower temperature. Under the condition of normal pressure, space rate 300 h-1, 140 ℃ and 125 W UV irradiation, the conversion of CH3OH was up to 14.2% with the DMC selectivity of 89.9% over Cu/NiO-V2O5/SiO2 catalyst.

Key words: photo-catalytic reaction, coupled semiconductor, carbon dioxide, methanol, dimethyl carbonate