Conversion of D-glucose to 5-hydroxymethylfurfural using Al₂O₃-promoted sulphated tin oxide as catalyst

Innovative catalysts to convert biomass carbohydrates in high value products are of an immense interest for the chemical industry and biorefineries. In this study, modified tin oxide (SnO₂) catalysts were synthesised and submitted to H₂SO₄ treatment (SO₄⁻²/SnO₂) and alumina doping (SO₄⁻²/Al₂O₃-SnO₂) using different calcination temperatures. The effect of these modifications on the catalyst performance were investigated by examining the catalysts properties and activity for the conversion of glucose to 5-hydroxymethylfurfural. The incorporation of alumina in the sulphated tin oxide catalyst and the use of low calcination temperatures increased the specific surface area and the acidity of the catalyst. This enhanced the chemo-selectivity of the conversion of glucose to 5-hydroxymethylfurfural. This catalyst was recovered after reaction by solvent washing and re-calcination; however, the recovery procedures were insufficient to avoid a decay of the catalyst performance during subsequent runs.