Constructing core-shell structured Au/Snβ@mesosilica composite for one-pot base-free conversion of glycerol to methyl lactate

Abstract

Herein, core-shell structured Snβ@mesosilica (MS) composite was constructed by oriented assembly of mesoporous silica on microporous Snβ zeolite. The mesoporous channels in the shell were verified vertically aligned to the Snβ core, rendering sufficient mass transfer between the shell and core. The resultant Snβ@MS was thereafter employed as the scaffolds for anchoring Au nanoparticles to develop a bifunctional Au/Snβ@MS catalyst for one-pot base-free conversion of glycerol to methyl lactate (ML), which is regarded as a promising and sustainable route to ML production. Under optimum reaction conditions, a remarkable activity with 98.2% glycerol conversion and 91.9% ML selectivity was achieved. More importantly, the introduction of mesoporous silica shell can efficiently modify the Lewis/Brønsted acid ratio of Snβ@MS, thus inhibit the side reactions. While the confinement effects could protect the highly dispersed Au nanoparticles against sintering. Accordingly, a high stability and recyclability was achieved over the Au/Snβ@MS catalyst.