Yolk–shell type carbon–silica nanoarchitecture with dispersed and stabilized Ru nanoparticles for enhanced hydrogenation of aromatic compounds

Abstract

Hydrogenation of aromatic rings can be used not only for synthesis of fine chemicals, but also for hydrogen storage and transportation using organic hydrides. In this paper, a yolk–shell structured SiO₂@Ru@NC catalyst, which was successfully synthesized by a strategy combining a modified Stöber method and vacuum-assisted impregnation, revealed excellent catalytic activity in dimethyl terephthalate (DMT) hydrogenation to dimethyl 1,4-cyclohexanedicarboxylate (DMCD), which is a green chemical reagent and precursor for high-value chemicals. Characterization results showed that highly dispersed Ru NPs with subnanometer size distribution were encapsulated in the yolk–shell nanoarchitecture and the mesoporous shell could ensure unhindered diffusion of reactant molecules. Moreover, yolk–shell structure-induced interaction of Ru and the carbon shell allowed for tuning the electronic structure of the Ru species, which in turn could regulate the catalytic properties. The yolk–shell nanoarchitecture catalyst offers advantages of low active metal loading, and excellent activity and stability, and thus can expand applications of ultra-low loaded precious metal catalysts in catalytic conversion of aromatic compounds.