Highly efficient catalytic conversion of cellulose into acetol over Ni–Sn supported on nanosilica and the mechanism study

Abstract

Selective conversion of cellulose into high value-added C3 chemicals is a great challenge in biorefinery due to the complicated reaction process. In this work, 61.6% yield of acetol was obtained by one pot conversion of cellulose using Ni–Sn/SiO₂ catalysts. A series of characterization methods including TEM, STEM-HAADF, EDS, AAS, XRD, XPS, H₂-TPR, Py-FTIR, and CO₂-TPD were carried out to explore the structure–activity relationship. The strong basicity of the catalysts was a key factor affecting the production of acetol. In addition, catalysts with the hydrothermally stable L-acid sites and no B-acid sites inhibited side reactions and ensured efficient conversion of cellulose into small molecules. Further studies showed that the formation of the Ni₃Sn₄ alloy significantly promoted the acetol production, and its weak hydrogenation activity inhibited further conversion of acetol. Noninteger valence tin species (Sn^δ+ and SnO_x) were formed both in Ni₃Sn₄ and Sn/SiO₂. These Sn species were the source of basic sites and the active sites for catalyzing cellulose to acetol. Under the synergistic catalysis of Sn/SiO₂ and the Ni₃Sn₄ alloy, cellulose was efficiently converted into acetol. This work provides guidance for the selective conversion of cellulose into C3 products.