Collaborative Research: Elucidation of the Effect of Dopant in CeO2(111) on the Nucleation and Growth of Metal Clusters through STM and Theory

In this project, Professors Jing Zhou of the University of Wyoming and Ye Xu of Louisiana State University will team up to elucidate the scientific principles in the formation and stability of nanoparticles supported on ceria (CeO2) via substitutional doping of the oxide, beyond what conventional synthesis methods can achieve. Metal nanoparticles supported on oxides are a class of functional nanomaterials that find a range of applications including heterogeneous catalysis, electronic devices, and gas sensing. Conventional methods assemble or deposit metal nanoparticles directly on an oxide, which often lose adhesion when exposed to high temperature and reactive chemicals. How to better anchor nanoparticles is therefore a fundamental challenge of broad relevance. The findings of this research will enable scientists to develop stable nanoparticles on oxides to power cutting-edge technological devices and chemical manufacturing processes. Graduate and undergraduate students will be involved in research that intersects chemistry, materials science, and computational modeling and translates scientific understanding into advanced materials, and will gain preparation for a research career that is in demand today. Substitutional doping means replacing some of the native metal cation in an oxide with a different metal. It is postulated to modify the nucleation and growth of metal nanoparticles on ceria, producing structures that are distinct from surface-deposited metals and offering a direct lever for affecting the size, density, chemical state, and stability of the nanoparticles. The UW-LSU team is uniquely positioned to create doped CeO2 thin films well suited for detailed characterization, and then apply a combination of advanced spectroscopy and microscopy tools and large-scale computational modeling to understand how the structure of ceria is modified by dopants, and how nanoparticles interact and evolve from dopants, with atomic-level details. Base metals including iron (Fe), cobalt (Co), and nickel (Ni) will be used as representative dopants. This project is driven by a critical scientific need for a clearer understanding of metal interaction with ceria lattice and its role in fascinating phenomena such as exsolution and strong metal-support interaction. 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.