Synergistic catalysis strategy of Lewis and Brønsted acids for superior aromatic production in biomass pyrolysis

Abstract

Catalytic pyrolysis is a versatile technology platform for converting biomass waste into valuable aromatics. However, achieving high yields and selectivity remains a significant challenge, particularly at low catalyst-to-biomass ratios. Herein, it is demonstrated that a novel bifunctional WO_x/HZSM-5 zeolite catalyst featuring synergistic Brønsted/Lewis (B/L) acid sites is capable of significantly boosting aromatic production. Structural characterization shows that the incorporation of tungsten species leads to the formation of W–O–Si/Al structures, which generate new Lewis acid sites and optimize the B/L acid ratio. This precise tuning results in an impressive carbon yield of aromatic of 18.66 wt% with a catalyst-to-demineralized pine ratio as low as 2:1, demonstrating exceptional catalytic efficiency. Furthermore, our analysis reveals a nonlinear quadratic relationship between the B/L ratio and carbon yield of aromatic, highlighting the complex interplay between catalyst structure and performance. These findings provide a strategic avenue for acid site engineering in zeolite catalysts, advancing the efficient conversion of biomass into high-value aromatics.