Abstract: Converting glucose into value-added products is a promising route for carbon utilization, and strongly influenced by the acidic properties and mass transport characteristics of solid acid catalysts. In this study, H-ZSM-5 nanosheets with varied Si/Al ratios were synthesized to investigate the effects of framework composition and b-axis length on glucose conversion. Increasing the Si/Al ratio decreased the density of acid sites but simultaneously reduced the b-axis length, enriched aluminum species near the external surface, and increased the relative abundance of Lewis acid sites, thereby enhancing the accessibility and utilization of active site. Consequently, H-ZSM-5_100 exhibited the highest site time yield, the lowest apparent activation energy, and the highest selectivity toward fructose and 5-hydroxymethylfurfural (5-HMF). Under optimized reaction conditions, H-ZSM-5_100 achieved a glucose conversion of 56.3% with a 5-HMF formation rate of 42.8 mmol h^-1 g^-1. These results demonstrate that the catalytic performance of H-ZSM-5 nanosheets is governed by the synergistic effects of framework composition, the distribution of acid site, and crystal morphology, providing guidance for the rational design of zeolite catalysts for biomass conversion.

Key words: H-ZSM-5 nanosheets, Glucose conversion, Si/Al ratio, Site accessibility, 5-Hydroxymethylfurfural