CuO-WO3-ZrO2的结构和性质对苯甲醛加氢反应催化性能的影响

采用共沉淀法制备了不同CuO和WO₃含量的CuO-WO₃-ZrO₂催化剂. 利用X射线衍射(XRD)、 扫描电子显微镜(SEM)、 X射线荧光光谱(XRF)、 N₂气物理吸附、 氢气程序升温还原(H₂-TPR)、 X射线光电子能谱(XPS)及程序升温脱附(TPD)等手段对催化剂的结构和表面性质进行了表征. 结果表明, WO₃的引入可以调变ZrO₂的晶型, 从而使催化剂的比表面积和孔径发生变化, 促进CuO在催化剂表面的分散, 并影响催化剂的酸碱性. 在苯甲醛加氢制备苯甲醇反应中, 以CuO质量分数为18%, WO₃质量分数为10%的CuO-WO₃-ZrO₂为催化剂时苯甲醛单程转化率达到92.03%, 产物苯甲醇的选择性为94.76%.

Effect of Structure and Properties of CuO-WO3-ZrO2 on Hydrogenation Catalytic of Benzaldehyde†

CuO-WO₃-ZrO₂ catalysts were prepared by co-precipitation method. Structures and surface properties of the catalysts were characterized by X-ray powder diffraction(XRD), scanning electron microscope(SEM), X-ray fluorescence(XRF), N₂ physisorption, temperature programmed hydrogen reduction(H₂-TPR), X-ray photoelectron spectroscopy(XPS) and temperature programmed desorption(TPD). Addition of WO₃ into CuO-ZrO₂ induced the transformation of ZrO₂ from monoclinic to tetragonal phases, improved the dispersion of CuO species, changed the acid-base properties of the catalysts as well as the catalyst textural features such as surface area and the average pore diameter. As a consequence, the catalytic performance for the hydrogenation of benzaldehyde to benzyl alcohol was greatly promoted by the introduction of WO₃. For the optimal catalyst containing 10%(mass fraction) CuO and 18%(mass fraction) WO₃, the conversion of benzaldehyde and the selectivity to benzyl alcohol reached 94.76% and 92.03%, respectively.