Coordination environment tuning of Ni-Sn catalysts by glu-carbon to optimize cellulose hydrogenolysis to oxygenated chemicals

Abstract

Bimetallic alloys are currently being developed as promising catalysts for the utilization of biomass. However, further study is required to understand their multifunctionality and to conduct computational screening. In this work, we synthesized Ni-Sn alloy-rich catalysts using glucose molecules to assist in cellulose hydrogenolysis. Our experimental findings demonstrated successful synthesis of Ni-Sn alloys (Ni3Sn2 and Ni3Sn4) with strong interactions and Lewis acid generation. Upon closer inspection, we discovered that glucose not only released reducing gas but also facilitates the formation of glu-carbon during calcination, which enhanced metal dispersion and modified the surface amphipathy. The multifunctional Ni-Sn catalyst directly converted to polyols and ketols in one-pot reaction, yielding a remarkable 54.6% of C2,3 polyols and 12.3% of C3,4 ketols. Density functional theory (DFT) provided the insight into the role of Ni3Sn2 and Ni3Sn4 alloys in producing C2-4 oxygenated chemicals. Specially, the Ni3Sn4 (20-1) facet enhanced the adsorption of key C2 intermediate through Ni-O bond formation via electrons transformation, while Ni3Sn2 (1-10) contributed to the catalytic activity for C3 intermediate. Furthermore, these alloy-rich catalysts exhibited superior thermal stability, effectively by preventing metal etching. This work presented a novel fabrication strategy for alloy-rich catalysts and provided an understanding of intrinsic mechanism underlying the catalytic roles of NixSny alloys in the hydrothermal conversion.