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Indexed by:期刊论文

Date of Publication:2018-09-15

Journal:APPLIED CATALYSIS B-ENVIRONMENTAL

Included Journals:SCIE、EI

Volume:232

Page Number:1-10

ISSN No.:0926-3373

Key Words:Levulinic acid; gamma-Valerolactone; CuAg/Al2O3 catalyst; Metal leaching; In situ reduction

Abstract:Metal leaching is a major issue in efficient production of gamma-valerolactone (GVL) from levulinic acid (LA) under mild reaction conditions. In this study, Ag was added to Cu-supported gamma-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 degrees C and 1.4 MPa H-2 pressure in tetrahydrofuran (THF). The strong interplay in the geometric and electronic effects between Cu and Ag was verified through XPS, H-2-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.