Abstract
Introducing transition-metal components to ceria (CeO2) is important to tailor the surface redox properties for a broad scope of applications. The emergence of high-entropy oxides (HEOs) has brought transformative opportunities for oxygen defect engineering in ceria yet has been hindered by the difficulty in controllably introducing transition metals to the bulk lattice of ceria. Here, we report the fabrication of ceria-based nanocrystals with surface-confined atomic HEO layers for enhanced catalysis. The increased covalency of the transition-metal-oxygen bonds at the HEO-CeO2 interface promotes the formation of surface oxygen vacancies, enabling efficient oxygen activation and replenishment for enhanced CO oxidation capabilities. Understanding the structural heterogeneity involving bulk and surface oxygen defects in nanostructured HEOs provides useful insights into rational design of atomically precise metal oxides, whose increased compositional and structural complexities give rise to expanded functionalities.
Original language | English |
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Pages (from-to) | 1081-1090 |
Number of pages | 10 |
Journal | ACS Central Science |
Volume | 8 |
Issue number | 8 |
DOIs | |
State | Published - Aug 24 2022 |
Funding
This work was supported by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division, Catalysis Science Program. Use of the Advanced Photon Source was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. Neutron total scattering measurements were conducted at the NOMAD beamline at the Spallation Neutron Source, Oak Ridge National Laboratory, which was sponsored by the Scientific User Facilities Division, Office of Basic Sciences, U.S. Department of Energy. Part of the work including Raman and STEM was conducted at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility. We thank Yujia Bian for the assistance during XAS experiments at the 10-BM beamline at the Advanced Photon Source at Argonne National Laboratory and Harry M. Meyer III at Oak Ridge National Laboratory for XPS acquisition and analysis.