Efficient and Sustainable Hydrogenation of Levulinic Acid to γ-Valerolactone in Aqueous Phase over Ru/MCM-49 Catalysts

Abstract

The hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) is an essential reaction step to produce value-added renewable chemicals and fuels. In this study, it is demonstrated that the dispersed state of metal and the acid properties of the support can be tuned directly in the synthesized stage for the Ru/MCM-49 catalysts. The average metal particle size of Ru was found at ∼2.0 nm, and strong metal–support interaction was observed for the Ru/MCM-49(DP) catalyst. Mesopores presented can enhance the conversion rate for LA to GVL. The presence of a higher amount of Lewis acid sites can promote the ring closure esterification of the intermediate 4-HPA. High catalytic activity with a TOF value of >3000 h–1, as well as excellent reusability, were achieved by Ru/MCM-49(DP). The agglomeration of Ru particles and the coke formation were thought to be responsible for the deactivation of the catalyst.