Size-Dependent Pt Nanoparticle/Carbon-Catalyzed Hydrogenation of 6-Chloroquinoline

Probing the fundamental rules of different types of active sites on Pt nanoparticles is highly desirable for the rational design of catalysts. Herein, the function of each type of active site on Pt nanoparticles has been identified via investigating the hydrogenation in seven carbon-supported Pt nanoparticles with different sizes. Kinetic study and model calculations demonstrate that Pt edge atoms play a dominating role in H2 dissociation, while the hydrogenation of 6-chloroquinoline is achieved on the relatively flat Pt(111) and (100) atoms by activated H atoms spilled from Pt edge atoms. The optimized Pt nanoparticles with a size of 1.36 nm exhibit the highest number of edge atoms for the catalytic activity. Meanwhile, the increase in the Pt nanoparticles size results in a growing adsorption strength of 6-chloroquinoline, further leading to a reduction in the selectivity of the target product. The insights reported here may pave the way for the rational design of highly active and selective Pt nanoparticles for hydrogenation.