中文摘要：

针对H3PW12O40（HPW）的比表面积小和不易回收利用等缺点，分别采用浸渍法、溶胶一凝胶法和以离子液体为模板剂的溶胶-凝胶法制备了HPW／SiO2催化剂，采用傅里叶变换红外光谱、X射线衍射、N2物理吸附和吸附氨的程序升温脱附等技术对催化剂样品进行了表征，并考察了其对苯硝化反应的催化性能．结果表明，所制备的催化剂样品都保持了HPW原有的Keggin结构．浸渍法制备的催化剂的比表面积（475．2m^2/g）较小，使用4次后硝基苯的收率由82．4％下降到70．7％；溶胶-凝胶法制备的催化剂的比表面积（498．6m^2／g）居中，使用4次后硝基苯的收率由85．1％下降到79．6％；以[emim]BF4离子液体为模板剂，采用溶胶-凝胶法制备的催化剂含有介孔结构，比表面积（558．5m^2／g）最高，使用4次后硝基苯的收率由84．7％下降到79．9％．不同方法制备的HPW／SiO2催化剂具有较高的催化苯硝化反应活性和较好的稳定性．

英文摘要：

Silica-supported H3PW12O40 catalysts were prepared by the impregnation method, sol-gel technique, and sol-gel technique using ionic liquids as the template, respectively, to solve the problems of H3PW12O40 such as low surface area, difficult separation, and reuse. The catalysts were characterized by means of Fourier transform infrared spectroscopy, X-ray diffraction, N2 adsorption, and NH3 temperature-programmed desorption. Their catalytic performance for the nitration of benzene was evaluated. The results revealed that H3PW12O40 in all the catalyst samples kept its Keggin structure. The specific surface area of the H3PW12O40/SiO2 catalyst prepared by the impregnation method was 475.2 m^2/g, and the nitration of benzene over it decreased from 82.4 % to 70.7% after 4 runs. The specific surface area of the H3PW12O40/SiO2 catalyst prepared by the sol-gel technique was 498.6 m^2/g, and the nitration of benzene over it decreased from 85.1% to 79.6 % after 4 runs. The H3PW12O40/SiO2 catalyst prepared by the sol-gel technique using [emim]BF4 as the template possessed mesoporous structure and a specific surface area of 558.5 m^2/g, and the nitration of benzene over this catalyst decreased from 84.7 % to 79.9 % after 4 runs. The three H3PW12O40/SiO2 catalyst samples showed higher stability and activity in the nitration of benzene.