Engineering the geometric and electronic structure of Ru via Ru–TiO2 interaction for enhanced selective hydrogenation

Abstract

Modulation of the metal–support interaction plays a key role in many important chemical reactions. Here, by adjusting the reduction method of the catalyst and introducing oxygen vacancies in TiO₂ to regulate the interaction between Ru and TiO₂, four supported Ru nanocatalysts with different encapsulation degrees and electronic structures were obtained. Ru nanoparticles (NPs) partially encapsulated by TiO₂ can achieve the selective hydrogenation of 6-chloroquinoline even at room temperature, with a TOF of 12 h⁻¹. Catalytic characterization and DFT calculations indicated that partially encapsulated Ru NPs not only provided active sites for H₂ dissociation, but also reduced the probability of Ru NPs being poisoned. Meanwhile, the oxygen vacancies on the surface of TiO₂ can adsorb 6-chloroquinoline molecules and provide additional active sites for hydrogenation via hydrogen spillover. Moreover, the enhanced electron transfer from oxygen-deficient TiO₂ to Ru made Ru electron-rich, which repelled C–Cl bonds and effectively prevented the production of dechlorination products.