Research progress on the role of common metal catalysts in biomass pyrolysis: a state-of-the-art review

Abstract

The past decades have witnessed increasing interest in developing pyrolysis pathways to produce high-quality chemicals from biomass. However, the numerous defects of bio-oil produced by biomass pyrolysis severely restrict its further application. A promising upgrading technology is considered to be the application of catalytic methods in biomass pyrolysis. Among various catalysts, metal catalysts have been well developed due to their flexible tailorability and unique characteristics. This review is dedicated to revealing the reasons for the biomass conversion pathways catalyzed by different metal catalysts (single and multi-metal catalysts, including Na, Mg, Al, K, Ca, Ti, Fe, Co, Ni, Cu and their combinations) and the conversion mechanisms of metal catalysts in the catalytic process. The interaction between different metal catalysts and the reasons why the combination improves catalytic activity were also introduced. At last, the research trends and perspectives on future development of metal catalysis in the field of biomass pyrolysis were proposed.