Strong electronic metal-support interaction of Pt/CeO2 enables efficient and selective hydrogenation of quinolines at room temperature

Abstract

Selectively catalytic hydrogenation of various quinolines in the presence of other reducible groups into the 1,2,3,4-tetrahydroquinoline compounds under mild conditions is a particular challenge for the heterogeneous catalysts due to the natural chemical stability of quinolines and poor chemoselectivity. Pt-based catalysts generally deliver good catalytic activity and selectivity for hydrogenation of quinolines with other reducible groups. However, the over-hydrogenated by-products are also often observed. Herein, Pt nanoparticles supported on CeO2 nanorods (Pt/NR-CeO2) realized highly efficient and chemoselective hydrogenation of various functionalized quinolines at room temperature. The unusual catalytic performance can be attributed to the strong electronic metal-support interactions (EMSI) between Pt and NR-CeO2 with the abundant surface oxygen vacancy, resulting in the enhanced electronic density of Pt nanoparticles. Subsequently, the modulated electronic structure of Pt enables the efficient hydrogen activation at room temperature, leading to a TOF of 546 h−1 of Pt/NR-CeO2 for the selective hydrogenation of 6-chloroquinolines. Density functional theory calculations also reveal that the high electron density of Pt benefits the desorption of the hydrogenated products and thus avoids the over-hydrogenation effectively.