生物质燃气变换-甲烷化双功能催化剂研究进展

生物质燃气在达到居民使用标准前必须进行提质，变换-甲烷化工艺单元可同时降低CO含量和提高燃气热值，因此研发适合生物质燃气的变换-甲烷化双功能催化剂显得尤为重要。在已广泛研究的单功能水气变换和甲烷化催化剂基础上，近年来国内外对变换-甲烷化双功能催化剂也开展了诸多探究。本文从催化剂组成、制备方法和反应机理三方面对变换-甲烷化双功能催化剂进行了综述，详细介绍了适用于该种催化剂的活性组分、助剂与载体，比较分析了浸渍法、共沉淀法等传统制备方法与火焰喷雾燃烧法、等离子体分解法等新颖制备方法，并对变换-甲烷化双功能催化剂进行了总结和展望，指出未来制备催化剂时助剂可根据具体要求选择性添加，廉价的矿石可替代成为有竞争力的催化剂载体，变换-甲烷指出化机理可借助多种材料表征以及理论计算而获悉。

Research progress of bifunctional catalysts for methanation coupling with water gas shift of biogas

It is essential to upgrade the biogas in order to meet the standard for downstream users. The integrated unit of methanation coupling with water gas shift could simultaneously reduce the CO content and increase the heating value of biogas. As a result, it is crucial to develop the corresponding bifunctional catalysts which can catalyze water gas shift and methanation simultaneously. On the basis of the widely developed catalysts for methanation or water gas shift, the bifunctional catalysts have also been preliminarily investigated. In this paper, the research progress of bifunctional catalysts for methanation coupling with water gas shift is reviewed from three aspects of catalyst composition, preparation method and reaction mechanism. The active metals, promoters and the support of the catalyst are introduced. The traditional preparation methods including impregnation and coprecipitation are compared with some novel methods such as flame combustion and plasma decomposition. Besides, the conclusion and prospect are also made. The promising preparation of the bifunctional catalysts is to selectively add promoters and to utilize cheap minerals as catalyst support. Various characterization techniques and theoretical calculations would be helpful to understand the mechanism of water gas shift coupling with methanation.