CHE 598 Seminar: Reactant-induced activation of Rh/CeO2 catalyst for N2O decomposition

About the event

SPEAKER: Yi Liu, Ph.D. Candidate, WSU Voiland School of Chemical Engineering and Bioengineering

BIOGRAPHY:

Yi Liu is a 3rd year Ph.D. candidate in Chemical Engineering at Washington State University’s Voiland School of Chemical Engineering and Bioengineering. Her research focuses on developing effective catalysts for nitrous oxide (N₂O) decomposition to mitigate greenhouse gas emissions and advance transportation emission control technologies. Yi received her master’s degree in Material Science and Engineering from National University of Singapore and her bachelor’s degree in Textile Engineering from Donghua University.

ABSTRACT:

Transportation is the second largest source of N₂O emissions, but effective emission control remains challenging since most transportation-related emissions occur at low temperatures. With increasingly stringent emission regulations, enhancing catalytic performance for N₂O removal is of great importance. In this work, we propose to use calcination temperature to control Rh-CeO2 interactions and study catalytic N2O decomposition behavior to guide the further design of catalyst for effective N2O emission control. Advanced characterization techniques (XAS, DRIFTS, etc.) reveal that single atom Rh with different oxidation states and coordination environment is successfully introduced by changing calcination temperatures. Notably, a reactant-induced activation after one reaction cycle is observed for catalyst calcined at higher temperature, with the catalyst shows a decrease in T50 value of more than 70 0C. N2O decomposition reaction results in oxidizing Rh species into a similar oxidation state while Rh-CeO2 interface shows a pivotal role in activating surface oxygen species. Reduced oxygen vacancy and storage capacity after high temperature calcination help preserve active oxygen species, which acts as active sites at the next reaction cycle to enhance catalytic performance. This study provides significant insights in understanding the critical role of support and metal-support interface for catalytic N2O decomposition.