Catalytic fast pyrolysis of maize straw with a core–shell ZSM-5@SBA-15 catalyst for producing phenols and hydrocarbons

Zeolites have been widely used as catalysts in the catalytic pyrolysis of biomass to produce biofuels and/or bio-based chemicals, which could lead to the replacement of fossil sources by renewable ones. However, conventional zeolites often suffer from diffusion resistance for large intermediate oxygenates. To solve this problem, a micro/mesoporous core–shell composite zeolite ZSM-5@SBA-15 was prepared and employed as a catalyst in the catalytic pyrolysis of maize straw. ZSM-5@SBA-15 was synthesized by crystallizing mesoporous silica on the external surface of ZSM-5 using the triblock copolymer Plunoric P123 as the template. The core–shell and hierarchical structures were verified using PXRD, TEM, and N₂ sorption experiments. In the catalytic pyrolysis of maize straw, ZSM-5@SBA-15 significantly enhanced the yield of valuable phenols and hydrocarbons in bio-oil, compared to ZSM-5 and SBA-15. The results demonstrated the potential application of micro@mesoporous core–shell composite zeolites in the catalytic pyrolysis of biomass.