Catalytic Glucose Conversion over Zeolitic Stannosilicates: A Comparative Study of Structural Properties

For the sustainable development of carbon neutrality, research on converting biomass-derived resources into chemical feedstock is essential. Specifically, the catalytic conversion of abundant glucose to 5-hydroxymethylfurfural (5-HMF) is receiving significant attention due to the excellent usability of 5-HMF. In this study, we prepared the stannosilicate MWW precursor (Sn-MWW(P)) and subsequently converted it into three different structure types, i.e., Sn-MWW(3D), Sn-MWW(2D), and Sn-Beta(IT), through calcination, delamination, and interzeolite transformation, respectively. The structural properties of each catalyst, the chemical states of framework Sn, and the concentrations of silanol and Brønsted and Lewis acid sites were analyzed using various characterization methods. These synthesized stannosilicates were then employed in a series of glucose conversion reactions, and the glucose conversion and yields of fructose and 5-HMF were evaluated according to the physicochemical properties of each catalyst. As a result, Sn-MWW(3D) exhibited the best catalytic performance in this study due to the uniformly dispersed Sn content, appropriate ratio of Brønsted and Lewis acid sites, and hydrophobicity resulting from a few structurally derived silanol groups. Overall, this study provides valuable insights into the potential of stannosilicate catalysts for biomass conversion, emphasizing the importance of the catalyst structure and physicochemical properties in achieving high catalytic activity.