Abstract
The impact of surface reconstruction of a model perovskite, SrTiO3 (STO), on CH4 activation for combustion and oxidative coupling was previously revealed that the reaction rate was proportional to the creation of Sr-terminated step sites. Doped perovskites (SrTi1−xMxO3, M=metal dopant) present yet another form of reconstruction throughout the surface and the bulk, where the metal dopant can migrate in and out of the perovskite lattice, also known as “intelligent behavior”. In this work, understanding the interplay between perovskite surface reconstruction (surface termination) and the “intelligent behavior” is tackled for the first time, and the catalytic consequences are probed with CH4 combustion as a model reaction. A set of experimental techniques, including XRD, Raman spectroscopy, X-ray adsorption spectroscopy, kinetic measurements, as well as DFT calculations were used to understand the catalytic behavior of the reconstructed surfaces of Ni and Cu-doped STO for methane combustion. We found that during methane oxidation, the diffusion of Ni and Cu into the lattice due to the “intelligent behavior” is accompanied by Sr enrichment on the surface of the perovskite. This Sr-enrichment process is reversible when Cu or Ni species exsolute as clusters/nanoparticles upon H2 treatment. Such a surface reconstruction is found to greatly impact the catalytic activity of doped perovskites towards methane combustion.
| Original language | English |
|---|---|
| Article number | 113672 |
| Journal | Catalysis Today |
| Volume | 416 |
| DOIs | |
| State | Published - Apr 1 2023 |
Bibliographical note
Publisher Copyright:© 2023 Elsevier B.V.
Funding
This research is sponsored by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division, Catalysis Science program. Part of the work including XRD and SEM was conducted at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility. 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 No. DE-SC0012704 . Beamline operations were supported in part by the Synchrotron Catalysis Consortium ( U.S. DOE, Office of Basic Energy Sciences , Grant No. DE-SC0012335 ). This research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under contract no. DE-AC02–05CH11231 . Notice: This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05–00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan )
| Funders | Funder number |
|---|---|
| Synchrotron Catalysis Consortium | |
| U.S. Department of Energy | DE-SC0012335, DE-AC02–05CH11231 |
| Office of Science | |
| Basic Energy Sciences | |
| Brookhaven National Laboratory | DE-SC0012704 |
Keywords
- Doped perovskites
- Methane combustion
- Surface reconstruction
- “intelligent behavior”