Catalytic reforming of polypropylene to produce hydrogen: Influence of support characteristics and active metal type in catalyst

Abstract

Hydrogen production by catalytic pyrolysis of waste plastics has attracted extensive attention in recent years. This paper takes hydrogen production as the starting point. A variety of supported nickel catalysts were developed for the catalytic pyrolysis of polypropylene using a two-stage fixed bed reactor. Based on the better characteristics of bimetallic catalysts, calcium, magnesium, iron doped nickel bimetallic catalysts were prepared to explore the improvement effect of catalytic hydrogen production performance. The micromorphology, structure composition and active substance distribution of different supported catalysts and bimetallic catalysts were measured. The experimental results show that the catalyst with powdered activated carbon as the support has the best catalytic performance of hydrogen production. In a series of molecular sieve catalysts, the smaller the Si/Al ratio of the support, the higher the catalytic performance. Among the bimetallic catalysts, Fe-Ni bimetallic catalysts have better catalytic advantages than Ca-Ni and Mg-Ni bimetallic catalysts, which is closely related to the stable Fe-Ni alloy structure formed on the catalyst surface. In conclusion, the differences in catalytic performance between catalyst support and active metal discussed in this paper will provide theoretical support for the catalytic pyrolysis technology of plastics to produce hydrogen.