PChem Seminar – Dr. McEwen

About the event

Speaker: Dr. Jean-Sabin McEwen, Voiland School of Chemical Engineering and Bioengineering

Host: Dr. Ivan Popov

Title: Elucidating the Chemical Nature of Single-Site Catalysts from First Principles

Abstract: Achieving the single-atom limit represents the pinnacle of material efficiency in supported metal catalysts. Developing highly dispersed, single-site catalysts that are both cost-effective and catalytically efficient is therefore of significant interest. Although single-atom sites can be synthesized, there remains ongoing debate about whether these isolated atoms are the true active centers, or if the observed catalytic activity arises from metal nanoparticles—either undetected in initial microscopy studies or formed under reaction conditions. This uncertainty underscores the need for well-defined single-site catalysts and robust theoretical models to accurately identify the nature of the active sites. In this work, we investigate the low-temperature CO oxidation kinetics of Pt single-site catalysts supported on the “29” Cu surface oxide. Additionally, we compare the catalytic behavior of Rh/Cu(111) single-atom alloys (SAAs) with varying O₂ exposure to that of Pt/Cu(111) SAAs. To gain further insight into structure–activity relationships, we explore the structural and redox dynamics of the Cu(111)-supported “29” oxide surface, with particular focus on its transformation to the “44” oxide under reaction conditions—where “29” and “44” denote the unit cell dimensions of the respective oxide structures.

Bio: Dr. Jean-Sabin McEwen is an Associate Professor in the Voiland School of Chemical Engineering and Bioengineering at Washington State University, and is a Staff Scientist at the Pacific Northwest National Laboratory. He received his BS degree in Physics from McGill University, as well as his MS and Ph.D. degrees in Physics from Dalhousie University. Dr. McEwen won the NSF Career award in 2017 and was also named an influential early-career researcher by the American Chemical Society’s Industrial and Engineering Chemistry Research in 2018. In 2023, he won the Peter Sherwood mid-career professional award from the American Vacuum Society Applied Surface Science Division. He serves as the Secretary of the Pacific Coast Catalysis Society, and was President from 2019-2022. He also was previously a member for the Early Career Advisory Board of ACS Catalysis. Dr. McEwen currently has 118 peer-reviewed publications with over 6700 citations.