Construction of Acid–Base Dual Sites in Heterogeneous Catalysts for Effective Conversion of Biomass Molecules into 5‐Hydroxymethylfurfural

This review presents the latest developments in the field of acid-base bifunctional catalysts in 5-hydroxymethylfurfural (5-HMF) production. It focuses on the design principles of catalysts, the synergistic effects of active sites, and a deeper understanding of reaction mechanisms. The performance of various catalyst systems in hydrolysis, isomerization, and dehydration processes is explored, with a particular focus on the impact of acid and base site interactions on the selectivity and yield of 5-HMF. The employment of optimized acid-base bifunctional catalytic systems has been demonstrated to yield fructose-to-HMF conversion yields as high as 98.6%, while for glucose substrates, conversion yields can reach 93%. Notably, these catalytic systems can achieve a notable conversion efficiency of 53% when confronted with cellulose substrates characterized by intricate 3D network structures and pronounced crystallinity. This observation serves to underscore the efficacy of acid-base bifunctional catalytic strategies. Furthermore, the article addresses the current limitations of catalysts and future development directions, including the development of new catalysts and the optimization of reaction conditions. By summarizing existing research findings, this article aims to provide guidance for the application of acid-base bifunctional catalysts in the field of biomass conversion, facilitating their transition to industrial applications.