TiOx(x＜2)表面修饰Ni/TiO2-SiO2催化顺酐液相选择加氢合成γ-丁内酯

以TiO2-SiO2复合氧化物气凝胶为载体,制备了一系列Ni/TiO2-SiO2催化剂,并采用N2物理吸附-脱附、H2程序升温还原/脱附、X射线衍射及原位漫反射傅里叶变换红外光谱等技术对催化剂进行了表征,考察了载体中钛含量对催化剂结构、表面性质及其催化顺酐液相选择加氢合成γ-丁内酯反应性能的影响.结果表明,较小的Ni0...

Selective Hydrogenation of Maleic Anhydride to γ-Butyrolactone over TiOx (x ＜ 2) Surface-Modified Ni/TiO2-SiO2 in Liquid Phase

TiO2-SiO2 aerogel with different TiO2 content was prepared by the sol-gel method. Ni/TiO2-SiO2 catalyst samples were then prepared via impregnation and were applied to the selective hydrogenation of maleic anhydride (MA) to γ-butyrolactone (GBL). The catalyst samples were characterized by infrared spectroscopy, N2 adsorption-desorption, temperature-programmed reduction, X-ray diffraction, diffuse reflectance infrared Fourier transform spectroscopy, and H2 temperature-programmed adsorption-mass spectroscopy techniques. The characterization results indicated that smaller Ni0 species favored the formation of GBL. Meanwhile, TiOx (x < 2) species, produced by the partial reduction of TiO2, was generated during the reduction process. The formation of TiOx (x < 2) species effectively promoted the hydrogenation of C=O group. Therefore, the hydrogenation of carbonyl was affected by both the size of Ni0 and TiOx species. When the synergistic effect of small Ni0 and TiOx species existed, the catalyst showed higher hydrogenation activity for C=O group.