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采用沉淀法和溶剂热法合成了三种具有相同晶型但不同孔径的四方ZrO_2(t-ZrO_2),以此为载体,采用沉积沉淀-硫酸锌溶液中还原的方法制备了Ru-Zn/ZrO_2催化剂,考察了Ru-Zn/ZrO_2催化剂的孔径对苯部分加氢性能的影响.采用粉末X射线衍射(XRD)、N_2物理吸附、电感耦合等离子体原子发射光谱(ICP-AES)、CO化学吸附、X射线光电子能谱(XPS)、X射线吸收近边结构(XANES)、X射线激发俄歇电子能谱(XAES)、H_2程序升温还原(H_2-TPR)和透射电子显微镜(TEM)等手段对载体和催化剂进行了系统的表征.研究表明,在苯部分加氢反应中,Ru-Zn/ZrO_2催化剂的孔径对环己烯的选择性有显著影响.随催化剂孔径的增大,苯的转换频率(TOF)基本不变,环己烯初始选择性(S0)则逐渐升高,孔径为11.7 nm的ZrO_2(ZrO_2(11.7))负载的Ru-Zn/ZrO_2(11.7)催化剂的S0及得率最高,分别可达88%和54%.结合催化剂的表征和加氢结果,讨论了孔径影响苯部分加氢活性和选择性的原因.
Three kinds of tetragonal ZrO 2 (t-ZrO 2) with the same crystal shape and different pore diameters were synthesized by precipitation and solvothermal methods. Ru-Zn / ZrO 2 was prepared by reduction with deposition-precipitation method The influence of the pore size of Ru-Zn / ZrO 2 catalyst on the hydrogenation performance of benzene was investigated.The effects of the pore size of Ru-Zn / ZrO 2 catalyst on the hydrogenation performance of benzene were investigated by X-ray powder diffraction, N 2 physical adsorption, ICP-AES, CO chemisorption , X-ray photoelectron spectroscopy (XPS), X-ray absorption near edge structure (XANES), X-ray excitation Auger electron spectroscopy (XAES), H 2 temperature programmed reduction (H 2 TPR) and transmission electron microscopy The results show that the pore size of Ru-Zn / ZrO 2 catalyst has a significant effect on the selectivity of cyclohexene in the partial hydrogenation of benzene.With the increase of the catalyst pore size, the conversion of benzene (TOF) and the initial selectivity of cyclohexene (S0) increased gradually. The S0 and yield of Ru-Zn / ZrO_2 (11.7) catalyst supported on ZrO_2 (11.7) The highest, up to 88% and 54% respectively.Combining with the catalyst characterization and hydrogenation results, we discussed the pore Effect of partially hydrogenated benzene reasons of activity and selectivity.