Selective hydrogenolysis of agricultural straw-based cellulose to propylene glycol and acetol over acidic WOx/ZrO2

Abstract

WO_x/ZrO₂ is effective in the hydrogenolysis of cellulose to C₃ products but the active sites on the W–Zr interfaces are hardly controlled. Herein, we prepared WO_x/ZrO₂ catalysts with active WO_x species by simply varying the reduction temperatures, which selectively achieved C₃ alcohol formation. A series of characterizations showed that increased reduction temperatures (400–600 °C) led to the formation of more dispersed WO_x, while higher reduction temperatures (>600 °C) contributed to producing aggregated WO₃ and W₂C. At 600 °C, the dispersity of WO_x peaked with a W⁵⁺/∑Wⁿ⁺ ratio of 19%, providing abundant Lewis acid sites and oxygen vacancies (Vo), which were the active sites for glucose isomerization to fructose and C–C cleavage of fructose. A selectivity of 48% for C₃ alcohols was obtained over the optimized WO_x/ZrO₂(600 °C) + Ru/AC catalyst.