Research progress of catalysts for catalytic steam reforming of high temperature tar:A review

Catalytic steam reforming is a meaningful strategy to produce syngas from high temperature tar. High temperature tar is the by-product of coal or biomass pyrolysis under high temperature conditions, which is a complex mixture containing millions of components. Catalytic steam reforming of high temperature tar can efficiently remove tar and convert the complex tar compounds into non-condensable gaseous products, such as H2, CO, CH4, CO2. Catalysts play an important role in catalytic steam reforming of high temperature tar. This review summarizes the development of catalysts for tar and model compounds steam reforming. Catalyst system can be divided into three parts, including active metal, promoter and support. The structure, morphology and composition of the catalyst would affect the catalytic performances and reaction mechanism. Analyzing steam reforming reaction mechanism of high temperature tar and model compounds is of great significance for catalysts synthesis and development. The reforming gas can be divided into -H, –OH and -O groups and the tar model compounds dissociate on the catalyst surface, generating free radicals through CC, CO and CH bonds cleavage to form CxHy and H2.