Highly Dispersed Ruthenium Nanoparticle-Embedded Mesoporous Silica as a Catalyst for the Production of γ-Butyrolactone from Succinic Anhydride

Abstract

In this study, a novel, strategic method was developed for the synthesis of a mesoporous silica catalyst embedded with ruthenium nanoparticles (RuNPs/SiO2) by combining the polyol and modified sol gel methods. By applying this new procedure, uniformly synthesized ruthenium nanoparticles with an average size of 3.8 nm and 95% spherical shape were highly dispersed in the mesoporous silica support material. Coordinated carbony l groups of PVP remaining from the synthesis of the RuNPs were effectively removed by the thermal treatment (calcined at 573 K for 4 h) and the sythesized RuNPs/SiO2 catalysts were reduced under hydrogen at 20 bar for 2 h. These catalysts were analyzed using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IA), N-2 adsorption-desorption, and X-ray ipfraction (XRD). After the thermal treatment and the reduction procedure, the size and shape of the embedded RuNPs were nearly unchanged, and the catalyst was active in the liquid-phase hydrogenation of succinic anhydride (SAN) to selectively form gamma-butyrolactone (GBL) with a maximum yield of 90.1%. This novel catalyst preparation is a potentially useful method for the synthesis of metal nanoparticles as heterogeneous catalysts.