5-HMF has attracted intense attention because it links natural biomass resources to industrial chemistry. The furanic compound can be upgraded into fuels, solvents, polymers and fine chemicals that would otherwise require petroleum feedstocks. As fossil fuel reserves deplete and pollution concerns mount, demand for bioenergy and biochemical research has surged, and 5-HMF is widely regarded as a key platform molecule in that transition. Direct one-step conversion from cellulose suffers from extremely low yields, so most researchers, including this team, choose glucose as the starting material.

The central obstacle is glucose isomerization. Glucose is an aldose sugar, but the dehydration chemistry that produces 5-HMF proceeds far more readily from fructose, a ketose. Converting glucose into fructose in situ, and then dehydrating the fructose into the furan ring, requires a catalyst that combines Lewis acid sites, typically metal centers such as chromium(III), with Brønsted acid sites such as sulfonic acid groups. Getting the balance and the spatial arrangement of these two acid functions right has remained one of the challenging steps in the whole conversion process.

To address this, the team prepared a metal chromium-loaded sulfonated mesoporous carbon-based solid acid catalyst, abbreviated Cr-SO3H-CSA, with a large average pore size of 7.844 nanometers and a high acidity of 14.304 millimoles of ammonia adsorbed per gram of catalyst. They also prepared a chromium-loaded sulfonated mesoporous silica-based solid acid catalyst, Cr-SO3H-MCM41, built on the classic ordered mesoporous silica MCM-41 first described in 1992 through a liquid-crystal templating mechanism. Both catalysts carry the same active chemistry, chromium Lewis acid sites and sulfonic Brønsted acid sites, but on very different supports.

When tested for the catalytic conversion of glucose to 5-HMF, the two catalysts delivered yields of 96.43 percent and 79.45 percent respectively. Compared with other types of solid acids reported in the literature, including sulfonated carbon materials, functionalized mesoporous silicas, zeolites such as Cu-Cr/ZSM-5, ion exchange resins modified with chromium(III), and lignin-derived ordered mesoporous carbons, the catalysts prepared in this study exhibit superior catalytic performance for the conversion of glucose to 5-hydroxymethylfurfural. The roughly seventeen-point gap between the two supports is the study’s most striking technical finding.

The authors demonstrate that the structure of the catalyst support has a significant impact on the catalytic effect. Mesoporous carbon offers a flexible, amorphous polycyclic aromatic framework whose surface chemistry can be tuned during sulfonation, and whose large pores of 7.844 nanometers provide generous transport channels for bulky sugar molecules. Mesoporous silica, by contrast, presents a rigid inorganic matrix with well-defined but structurally different porosity and surface silanol groups. The way sulfonic acid groups anchor, the dispersion of chromium species, and the accessibility of active sites all depend on which of these frameworks carries them.

Large pore size matters for a practical reason. Glucose and the intermediates in the isomerization-dehydration sequence are bulky, highly hydrated molecules, and narrow pores can restrict diffusion, promote side reactions such as humin formation, and limit contact between the sugar and the acid sites. A support with wide mesopores keeps the reaction pathway open, allowing glucose to reach the chromium Lewis acid sites where isomerization occurs and then the neighboring sulfonic Brønsted acid sites where fructose is dehydrated into the furan ring. High acidity, quantified here by ammonia adsorption at 14.304 millimoles per gram, ensures that enough strong acid sites exist to drive both steps at useful rates.

The result also fits a broader pattern in biomass catalysis. Previous work has shown that the interplay of Lewis and Brønsted acid catalysts governs glucose and fructose conversion to 5-HMF and levulinic acid in aqueous media, and that sulfonic acid functionalized supports, whether carbon or silica, can serve as efficient solid acid catalysts for sugar upgrading. Studies of mesoporous carbon and silica catalysts for esterification and biodiesel fabrication have likewise revealed that matrix surface composition and porosity strongly influence performance. The Beijing Forestry University study extends that structure-performance principle to the glucose-to-5-HMF reaction and quantifies it across two support families.

The work expands the choice of catalysts for efficient conversion of biomass into 5-HMF and provides insights into the effect of support structure on catalyst preparation. For biorefineries, a heterogeneous solid acid that approaches quantitative yield from glucose is attractive because it can be separated from the reaction medium and reused, avoiding the neutralization and waste issues associated with homogeneous mineral acids. The chromium centers and sulfonic groups are immobilized on the support, so the catalyst can in principle be recovered by filtration while the sugar solution moves on to product isolation.

The research was carried out at the School of Materials Science and Engineering of Beijing Forestry University and supported by the National Key Research and Development Program of China under the 14th Five-Year Plan, grants 2023YFD2200500 and 2023YFD2200504. The authors declare no known competing financial interests. Published on 16 October 2026 in the Journal of Materials Science, the study arrives as lignocellulosic biorefineries move from deep eutectic solvent pretreatments and biphasic reaction systems toward catalysts that can handle raw glucose streams, and it suggests that support engineering, not just active-site chemistry, will shape the next generation of solid acid catalysts for renewable platform molecules.

Subject of Research: Effect of mesoporous carbon and mesoporous silica support structure on chromium-loaded sulfonated solid acid catalysts for converting glucose to 5-hydroxymethylfurfural

Article Title: Effect of the structure of mesoporous carbon-based and mesoporous silica-based solid acid catalysts on the catalytic conversion of glucose to 5-HMF

Article References: Zhang, D., Xu, X., Zhang, R., Zhang, Z., Zhang, X., & Yao, C. (2026). Effect of the structure of mesoporous carbon-based and mesoporous silica-based solid acid catalysts on the catalytic conversion of glucose to 5-HMF. Journal of Materials Science. https://doi.org/10.1007/s10853-026-13955-7

Image Credits: AI Generated

DOI: 10.1007/s10853-026-13955-7

Keywords: 5-HMF, solid acid catalysts, mesoporous carbon, mesoporous silica, glucose isomerization, biomass conversion, chromium catalysts, biorefinery, Journal of Materials Science, catalyst support structure, Effect, structure