Monolithic Biochar-Supported Cobalt-Based Catalysts with High-Activity and Superior-Stability for Biomass Tar Reforming

Abstract

In this paper, monolithic biochar-supported cobalt-based catalysts with unique long and through mesopores were synthesized based on the biological channels of biomass materials through simple impregnation and carbonization and evaluated in a biomass tar model (toluene) steam reforming and biomass pyrolysis tar decomposition reactions. Regular channels with a diameter of around 20-40 μm are well retained after carbonization for the monolithic biochar. Co0, Co-Fe and Co-Ni alloy nanoparticles are formed and dispersed uniformly on the surface of the channels of catalyst PC@Co2, PC@Co1Fe1, and PC@Co1Ni1, which are anchored firmly by graphitic carbon layer. At 700 oC, the carbon deposition resistance of PC@Co1Fe1 and PC@Co1Ni1 was significantly improved due to the introduction of the Fe and Ni, and excellent performance were achieved during the 360 min continuous toluene reforming experiments. The average toluene reforming rate reached around 97 % and 85.3% by using PC@Co1Ni1 and PC@Co1Fe1 as the catalysts, and H2 and CO were the main product with a small amount of CO2 and CH4. PC@Co1Ni1 also showed high activity in the decomposition of biomass pyrolysis tar with a high average tar conversion efficiency of around 91% and excellent stability in a five-cycle test, and H2 yield was also significantly improved.