Organic-pillared vermiculite was applied as the support to fabricate Ru catalyst via adsorption-precipitation method. The catalytic performances of the catalyst were investigated for the selective hydrogenation of levulinic acid (LA) or methyl levulinate (ML) to γ-valerolactone (GVL). The 100% selectivity of GVL and 100% conversion of LA were obtained at 403 K, 4.0 MPa using water as solvent. Moreover, a good recyclability was observed even after 14 reaction cycles as a slight conversion decrease of the LA and no change of the selectivity of GVL. The Characterization of the fresh catalysts and reused catalysts were performed using various techniques including XRD, FT-IR, N2 adsorption-desorption, XPS and TEM. The catalytic tests and characterization data confirmed that the sample of Ru/Modified-Vermiculite can be taken as a robust and effective catalyst for the conversion of the LA to GVL.
The modified vermiculite supported-Ru catalyst has super activity and stability in the hydrogenation of levulinic acid to γ-valerolactone. Ru active components dispersed uniformly on the surface of organic modified vermiculite, and there was no obvious aggregation of the components. Even after fourteen cycles, levulinic acid conversion and γ-valerolactone selectivity remained 95% and 100%, respectively. The present work provides an efficient route for the preparing the Ru-based catalyst of excellent stability in the process of hydrogenation of levulinic acid.