粒子尺寸对Cu/MgO上1-辛醇转移脱氢反应的影响(英文)

Transfer Dehydrogenation of 1-Octanol to 1-Octanal over Cu/MgO Catalyst:Effect of Cu Particle Size

采用沉积-沉淀法制备了不同Cu粒子大小的Cu/MgO催化剂,并考察了Cu粒子大小对醇类转移脱氢制醛酮反应性能的影响.结果表明,Cu/MgO催化剂对一级脂肪醇的转移脱氢反应具有较高的催化活性.对于1-辛醇脱氢,随着Cu粒子的粒径由4.6nm增大到7.4nm,1-辛醛的收率由65%减小到55%,表现出显著的粒子尺寸效应.反应机理研究表明,醇首先在碱性MgO表面形成醇盐中间物种,随后在Cu纳米粒子上进一步脱去α-氢生成醛酮,同时脱去的氢在Cu纳米粒子上发生苯乙烯加氢反应,完成醇的转移脱氢反应循环.

Cu/MgO catalysts with different Cu particle sizes were prepared by a precipitation-deposition method and investigated for their activity in the transfer dehydrogenation of alcohols to carbonyl compounds.They were highly active for the conversion of primary aliphatic alcohols,e.g.1-octanol.With increasing Cu particle size from 4.6 to 7.4 nm,the aldehyde yield decreased from 65% to 55%,which showed a size effect.The copper particle abstracted an α-hydrogen from the reactive alkoxide intermediate formed on the surface of MgO and simultaneously catalyzed the hydrogenation of styrene.