Theoretical studies of hydrogen spillover mechanism for developing next generation automobile catalyst: A quantum chemical molecular dynamics study

Hydrogen spillover mechanism has earned intensive interest in the past decades because it plays a vital role in emerging technologies for the reduction of NOx in automobile exhausts. Hydrogen spillover arises in hydrogen-catalyzed reactions on supported metal catalyst. In the present study, we applied quantum chemical molecular dynamics (QCMD) to investigate the mechanism of the hydrogen spillover process on Pt/g-Al₂O₃ and on Pt/CeO₂ catalyst surfaces for the first time. The direct observation of dissociative adsorption of hydrogen and diffusion of hydrogen on Pt/g-Al₂O₃ and Pt/CeO₂ catalyst surfaces were successfully investigated. The diffusion of the hydrogen atom in the gas phase explains high reactivity observed in hydrogen spillover mechanism. The present study also indicates that the CeO₂ catalyst support has the strong metal support interaction on Pt, which may enhance the metal catalyst dispersions and rate of hydrogen spillover reaction.