【作者】 刘杰； 徐思民； 卫敏； David G.Evans； 段雪；

【Author】 Jie Liu;Simin Xu;Min Wei(Wu Zhou);David G.Evans;Xue Duan;State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology;

【机构】 北京化工大学化工资源有效利用国家重点实验室；

【摘要】 环己烯是一种非常重要的化工原料,广泛用于己二酸,尼龙,己内酰胺等精细化工品的合成[1]。苯选择性加氢制环己烯因其较传统的环己烯合成路线,如环己醇脱水、环己烷脱氢及Brich还原具有原料廉价,原子经济性高及操作工艺简单等优点,近年来备受研究者的关注[2]。本课题通过共还原铜镁铝水滑石浸渍的钌盐前体,并利用水滑石的记忆效应制备了系列的镁铝水滑石负载的钌铜双金属催化剂。此催化剂应用于苯液相选择性加氢反应表现出优异的催化性能(当Ru/Cu比为2/1时,150 oC,5.0 MPa,无添加剂情况下,环己烯最高产率可达44.0%)。CO-FTIR分析手段表明,在所制备的Ru-Cu双金属催化剂中,随着Cu含量的升高,Ru颗粒表面金属原子由低配位钌向高配位钌逐渐被铜原子簇覆盖。进一步结合理论计算发现,Cu对低配位点的表面Ru原子的覆盖,降低了环己烯在Ru表面的吸附能,有利于其脱附,防止了其进一步加氢生成环己烷。更多还原

【Abstract】 Cyclohexene is one of the most important commodity petrochemicals, as a raw material for the production of value-added adipic acid, nylons, caprolactam and other fine chemicals.[1] Recently, a growing interest has been focused on the generation of cyclohexene by selective hydrogenation of benzene due to its advantages over traditional production routes(e.g., dehydration of cyclohexanol, dehydrogenation of cyclohexane and Brich reduction), in terms of inexpensive feedstock, atomic economy and operational simplicity.[2] Herein, we report the fabrication of Cu-decorated Ru catalysts supported on Mg Al-LDH via a facile two-step procedure involving the reduction of Ru Cl3 impregnated CuM gA l-LDH by hydrogen followed by the rehydration of the resulting RuxCuy/Mg O-Al2O3 to RuxCuy/Mg Al-LDH. The resulting RuxCuy/Mg Al-LDH catalysts exhibit excellent catalytic behavior towards the selective hydrogenation of benzene to cyclohexene, reaching a maximum cyclohexene yield of 44.0% over Ru1.0Cu0.5/Mg Al-LDH catalyst at 150 oC and 5.0 MPa without employment of any additives.In situ CO-FTIR technique demonstrate that Cu preferentially deposit on the surface of low-coordinated Ru atoms in RuxCuy/Mg Al-LDH catalysts, resulting in a low adsorption energy of cyclohexene on the modified sites revealed by DFT calculations.更多还原