Collaborative Research: GOALI: Identifying the roles of atomically dispersed Rh, support interactions, and environmental conditions in automotive NO reduction catalysis

University Of Florida, Gainesville FL

Investigators

Abstract

Heterogeneous catalysis plays a vital role in keeping the environment clean. For example, catalytic converters in automobiles significantly reduce the environmental impact of the transportation sector by converting exhaust components to less harmful gases. Dramatic improvements in air quality since the 1970s in locations such as the Los Angeles basin underscore the enormous impact of heterogeneous catalysis on everyday life. Critical to the development of more efficient catalytic processes and the design of new catalytic materials is understanding the relationship between a catalyst's atomic structure and its function. It is expected that insights obtained during this research project will provide necessary information to guide the design of more effective catalysts, thereby enabling improvements in the performance and efficiency of catalytic converters. To promote unique educational opportunities provided by this research project, graduate students from the University of California-Santa Barbara and the University of Florida will visit Ford Motor Company's Research and Innovation Center in Dearborn, MI for three months each summer to continue research as visiting scholars. Undergraduate students will be involved in the research project and will learn from the topic through in-class modules. Three-way catalysts are the workhorse components of catalytic converters that achieve simultaneous oxidation and reduction of pollutants to less harmful species. Typical metals at the active sites of three-way catalysts are Platinum (Pt), Palladium (Pd) and Rhodium (Rh). While Pt and Pd typically promote oxidation reactions, Rh plays a crucial role in commercial catalysts because of its ability to reduce nitrous oxide (NO) to dinitrogen (N2). Despite its commercial importance, the mechanism of NO reduction on Rh active sites has remained largely elusive under relevant automotive working conditions. In this project, academic researchers will interface with an industrial partner to gain crucial mechanistic insights into the role of atomically dispersed Rh species in commercial three-way catalysts. Rigorous comparisons of the performance and mechanism of NO reduction chemistry under realistic conditions on atomically dispersed Rh and Rh clusters, as a function of environmental conditions and support composition, will be made. The research approach will combine kinetic studies, in-situ infrared and X-ray absorption spectroscopy, and density functional theory calculations. Results of this study will help guide the design of three-way catalysts and catalytic converter control systems for improved performance. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.