Cooperation between the surface hydroxyl groups of Ru–SiO2@mSiO2and water for good catalytic performance for hydrogenation of quinoline

Abstract

A well dispersed core–shell nanocatalyst, Ru–SiO₂@mSiO₂, with a Brunauer–Emmet–Teller surface area (S_BET) as high as 602 m² g⁻¹, has been prepared by a modified Stöber method and characterized by SEM, TEM, SAXRD and solid-state NMR. The catalyst shows a good catalytic performance for the hydrogenation of quinoline to 1,2,3,4-tetrahydroquinoline under mild conditions in water. Both the conversion and selectivity are up to 100%. Furthermore, the catalyst could be recycled up to five times without loss of both the activity and selectivity. It is postulated that the high performance of this novel catalytic system is related to the cooperation between the surface hydroxyl groups of the microporous shell of Ru–SiO₂@mSiO₂ and water as a solvent.