# Synthesis of Sulfated Sn–Zr Mesoporous Catalysts for the Selective Dehydration of Hexose‐Type Monosaccharides

## TL;DR

Scientists created a new catalyst that efficiently converts fructose into HMF, a key chemical for biofuels and materials.

## Contribution

A sulfated Sn–Zr mesoporous catalyst is developed with optimized Brønsted and Lewis acid sites for high HMF yield from fructose.

## Key findings

- SO4/Sn–Zr–SBA-15 achieves ≥70% HMF yield with ≈90% fructose conversion under optimal conditions.
- The catalyst's acid site balance and sulfate groups enhance its performance compared to other materials.
- Higher fructose concentrations were used successfully compared to prior studies.

## Abstract

Synthesis of combined Brønsted and Lewis acid sites in SBA‐15 by Zr and Sn incorporation onto the mesoporous support, followed by a sulfation procedure to get enhanced acid catalysts for fructose‐to‐5‐hydroxymethylfurfural (HMF) selective dehydration, is here studied. Different preparation methods are used to attain the Sulfated Sn–Zr–SBA‐15 material with adequate combination of Brönsted and Lewis acidity. Samples are characterized by using different analytical and spectroscopic techniques, results indicating a correlation between the preparation procedure and the acid characteristics of the materials. The latter are evaluated in the catalytic conversion of concentrated fructose solutions (30 wt%) into HMF in a biphasic system (water + iso‐butylketone/2‐butanol). The most efficient catalyst, SO4/Sn–Zr–SBA‐15 (Zr/Sn molar ratio = 1.98), yields ≥ 70% HMF at a substrate conversion of ≈90% under optimal reaction conditions (150 °C for 120 min.), these results being particularly relevant when considering the higher initial fructose concentrations here used compared to those typically employed in previous reports. This catalyst exhibits a higher ratio of Bronsted/Lewis (B//L) acid sites of moderate strength and a lower density of acid sites compared to the other catalytic samples evaluated, mainly due to the presence of well‐dispersed tin and zirconium species, as well as to the enhanced acidic properties provided by sulfate groups in the material.

The synthesized SO4/Sn–Zr–SBA‐15 shows high activity in fructose‐to‐5‐hydroxymethylfurfural (HMF) dehydration. Acid sites with positive synergy effect between metals and SO4
= improve catalytic behavior© 2025 WILEY‐VCH GmbH