合成气直接制C2含氧化合物Rh基催化剂中金属-助剂(载体)界面的构建

Construction of Metal⁃Promoter(Support)Interfaces within Rh based Catalyst for Direct Synthesis of C2 Oxygenates from Syngas

由煤、天然气或生物质经合成气直接制取乙醇等C2含氧化合物可以替代传统的石油和粮食路线,其意义重大。负载型助剂促进的金属Rh是实现该过程最有效的催化剂,其中Rh⁃助剂(载体)接触界面是发生目标反应的活性位,其面积的大小直接决定了该催化剂的性能,因此,近些年来人们尝试多种物理或化学方法来改进Rh基催化剂的制备过程,以最大化金属-助剂界面。我们简要介绍和评述了涂覆法、形成复合氧化物或合金、强静电吸附法、控制表面反应法和原子层沉积法等的原理、过程以及优缺点。通过结合上述合成方法,可制备出均一分布的、界面活性位结构确定的催化剂。

It is of great significance to produce C2 oxygenated compounds such as ethanol directly from CO hydroge⁃nation via coal,natural gas or biomass that can replace the traditional oil and food routes.The supported promoted⁃Rh is the most effective catalyst to realize this transformation.The Rh⁃promoter(support)contact interfaces are the active sites for the formation of C2 oxygenates from syngas,thus the contact interface areas directly determines the performance of the catalyst.Therefore,recently many researchers have been working on various physical or chemi⁃cal methods to improve the preparation process of Rh⁃based catalysts to maximize the metal⁃promoter interfaces.In this paper,the principle,process,advantages and disadvantages of these methods(coating,formation of composite oxide or alloy,strong electrostatic adsorption,controlled surface reaction method and atomic layer deposition)are briefly introduced and reviewed.Through the combination of the above synthesis methods,it is possible to prepare the catalysts with uniform distribution of well⁃defined active sites at the interface.