Abstract
Sintering poses a significant challenge to achieving the long-term stability of supported metal catalysts under reaction conditions. Here, we report a low-temperature catalyst redispersion mechanism, in which platinum single atoms, which aggregate into nanoparticles under Reverse Water Gas Shift (RWGS) conditions at elevated temperatures, fragment into atomically dispersed species upon cooling. Using multimodal operando characterization combined with first-principles theoretical modeling, we track the structural evolution of Pt single atoms supported on ceria nanodomes, deposited either on ceria or ceria–titania mixed oxides. We find that fragmentation is more pronounced when cooling occurs under RWGS conditions compared to CO alone, owing to a synergistic interplay of the effects of H2, CO2, and CO. The support architecture has a strong influence on the extent of redispersion: while CO alone induces fragmentation on ceria, interfacial confinement and vacancy pinning at the ceria–titania interface suppress restructuring. In contrast, RWGS conditions overcome these barriers, enabling redispersion across both supports. These findings point toward a pathway for catalyst stabilization via reaction-induced redispersion under mild conditions.
| Original language | English |
|---|---|
| Pages (from-to) | 19709-19720 |
| Number of pages | 12 |
| Journal | ACS Catalysis |
| Volume | 15 |
| DOIs | |
| State | Published - 2025 |
Funding
A.I.F. acknowledges support of the National Science Foundation grant 2452446. Y.L.’s effort at ORNL was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division, Catalysis Science program. H.Y.K acknowledges the financial support by the National Research Foundation of Korea (NRF) grant funded by the Korean government (Ministry of Science and ICT, MSIT) (RS-2023-NR077216), the Basic Science Research Program through the NRF funded by the Ministry of Education (RS-2021-NR060128). C.R. gratefully acknowledges the Rowland Fellowship through the Rowland Institute at Harvard. This research used beamline 7-BM (QAS) of the National Synchrotron Light Source II, a U.S. DOE Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory under Contract DESC0012704. Beamline operations were supported in part by the Synchrotron Catalysis Consortium (U.S. DOE, Office of Basic Energy Sciences, Grant DE- SC0012335). This research used a Hitachi2700C STEM of the Center for Functional Nanomaterials, which is a U.S. DOE Office of Science Facility, at Brookhaven National Laboratory under Contract DESC0012704.
Keywords
- In-situ
- catalyst-restructuring
- reaction-driven redispersion
- reverse water gas shift reaction
- single-atom catalysts