CoZn-ZIF-derived ZnCo2O4-framework for the synthesis of alcohols from glycerol

Abstract

As a widely used solvent, fuel and intermediate, the demand for ethanol continuously increases. Currently, ethanol is produced via sugar fermentation and hydration of ethylene. It is of great significance to convert abundant glycerol to ethanol. Herein, we report a novel Co/ZnO catalyst with nano-sized Co particles embedded in ZnO plates, which was obtained through calcination and reduction of CoZn-ZIF precursor, and its excellent performance in the synthesis of ethanol from glycerol. The transformation process from CoZn-ZIF to Co/ZnO-ZIF was characterized by TG-DSC, XRD, SEM, TEM and XPS. Characterization results indicated that rhombic dodecahedral composite consisting ZnCo₂O₄ spinel formed after calcination of CoZn-ZIF precursor, which also led to the formation of small Co particles that embedded in ZnO plates during reduction. Under optimal conditions, the best yield of ethanol reached 1.45 g-ethanol per g-cat per h at 210 °C over Co/ZnO-ZIF. On the basis of a series of controlled experiments, the reaction mechanism for the formation of alcohols from glycerol was proposed.