The Role of Mo Single Atoms and Clusters in Enhancing Pt Catalyst for Benzene Hydrogenation: Distinguishing Between Benzene Spillover and Electronic Effect
Zhuo Li, Fanchun Meng, Xinchun Yang, Yuntao Qi, Yong Qin, Bin Zhang
Abstract
Reactant spillover and electronic effects are two indistinguishable factors that influence MoO 3 promoters in benzene hydrogenation on Pt-MoO 3 catalysts. Previous studies have primarily focused on the significance of hydrogen spillover while neglecting the transfer of benzene and the electronic effect originating from MoO 3 . Herein, we synthesized Pt/CNT, Pt–Mo 1 /CNT with Mo single atoms, and Pt–Mo cluster /CNT with MoO x cluster promoters by using atomic layer deposition. The catalyst Pt–Mo 1 /CNT exhibited higher activity (3361.8 h –1 ) in benzene hydrogenation at 50 °C, which was twice as high as that of Pt/CNT. In contrast, the presence of closely interacting MoO x clusters with Pt nanoparticles inhibited the activity of the Pt catalyst. Kinetic experiments, DFT calculations, in situ FTIR, and AIMD simulations revealed that Mo single atoms on multiwalled carbon nanotubes did not alter the structure or electronic state of Pt nanoparticles but enhanced their activity by increasing benzene coverage via benzene spillover. On the other hand, although the hydrogen and benzene coverage increased with MoO x cluster promoters, changes in the electronic state of Pt nanoparticles resulted in a higher energy barrier for the rate-determining step.