论文部分内容阅读
以含巯基官能团有机硅烷修饰的介孔材料MCM-41和SBA-15为载体, 采用浸渍-氢气还原法制备了高分散和高活性的负载型Pd催化剂. X射线衍射、N2吸附-脱附和透射电子显微镜表征结果显示, 所制Pd催化剂Pd-SH-MCM-41和Pd-SH-SBA-15具有很好的长程有序结构、分布均匀的孔径、高比表面积及高度分散的Pd颗粒. 苯酚加氢反应结果表明, 以Pd-SH-MCM-41和Pd-SH-SBA-15为催化剂时, 在80oC, 1.0 MPa反应1 h, 苯酚转化率达99%以上, 环己酮选择性为98%. 它们的催化活性为商业Pd/C催化剂的5倍, Pd/MCM-41和Pd/SBA-15催化剂的3倍. 这可归因于介孔材料表面修饰的巯基官能团对Pd的锚定作用, 避免了Pd颗粒的团聚, 使其高度分散在介孔材料上.
The supported Pd catalysts with high dispersion and high activity were prepared by impregnation-hydrogen reduction using mesoporous MCM-41 and SBA-15 modified by mercapto-functional organosilane as catalysts. X-ray diffraction, N2 adsorption-desorption and transmission The results of electron microscopy showed that Pd-SH-MCM-41 and Pd-SH-SBA-15 have good long-range order structure, uniform distribution of pore size, high specific surface area and highly dispersed Pd particles. The results of hydrogenation showed that when Pd-SH-MCM-41 and Pd-SH-SBA-15 were used as catalysts, the conversion of phenol was above 99% and the selectivity to cyclohexanone was 98% %. Their catalytic activity is three times that of the commercial Pd / C catalyst and three times that of the Pd / MCM-41 and Pd / SBA-15 catalysts.This is attributable to the anchoring of the surface-modified mercapto-functional mesopores on Pd Role, to avoid the agglomeration of Pd particles, making it highly dispersed in the mesoporous material.