Metal leaching is a major issue in efficient production of γ-valerolactone (GVL) from levulinic acid (LA) under mild reaction conditions. In this study, Ag was added to Cu-supported γ-Al2O3 catalyst to suppress Cu leaching in the hydrogenation of LA into GVL. The CuAg/Al2O3 catalyst was reduced in situ during the reaction, and Cu leaching in the solution was significantly suppressed. The bimetallic catalyst without reduction pretreatment achieved approximately 100% yield to GVL and exhibited good reusability in nine consecutive cycles under mild reaction conditions of 180 °C and 1.4 MPa H2 pressure in tetrahydrofuran (THF). The strong interplay in the geometric and electronic effects between Cu and Ag was verified through XPS, H2-TPR, TEM, STEM/EDS, and XRD analyses. This paper extensively discussed the mechanism of Ag on preventing Cu leaching and the superiority of in situ reduction in solution over external reduction in gas.
All Science Journal Classification (ASJC) codes
- Environmental Science(all)
- Process Chemistry and Technology