Modification of Pt/SiO₂ with Mg(OH)₂ Improves Xylose to Xylulose Isomerization

Sugar compounds are an important part of biomass resources, and their catalytic conversion can prepare a series of platform compounds, such as lactic acid and polyols. One of the key steps is the isomerization of aldoses to ketoses. However, finding a simple method to efficiently convert aldoses to ketoses remains a great challenge. Herein, we report a core–shell structured catalyst, Pt/SiO₂@Mg(OH)₂, for the efficient conversion of xylose as well as the further conversion of xylose to xylulose. Xylose, a five-carbon sugar unit with the highest content in biomass, was used as the object of study to determine the optimal reaction conditions in the aqueous system by adjusting the loading amount of Mg(OH)₂, catalyst addition, reaction temperature, and reaction time: In the optimum aqueous conditions, the yield of xylulose was 23.61%. We also investigated the effect of solvent effects on the hydrothermal reaction and determined the optimal solvent ratio, the yield of xylulose reached 31.74% at H₂O:MeOH (8:2). We anticipate that this research result can provide a theoretical basis and reference for the industrialized production of subsequent sugar isomerization.