Abstract
Efficiently removing/converting methane via methane combustion imposes challenges on catalyst design: how to design local structures of a catalytic site so that it has both high intrinsic activity and atomic efficiency? By manipulating the atomic distance of isolated Pd atoms, herein we show that the intrinsic activity of Pd catalysts can be significantly improved for methane combustion via a stable Pd2 structure on a ceria nanorod support. Guided by theory and confirmed by experiment, we find that the turnover frequency (TOF) of the Pd2 structure with the Pd-Pd distance of 2.99 Å is higher than that of the Pd2 structure with the Pd-Pd distance of 2.75 Å; at least 26 times that of ceria supported Pd single atoms and 4 times that of ceria supported PdO nanoparticles. The high intrinsic activity of the 2.99 Å Pd-Pd structure is attributed to the conductive local redox environment from the two O atoms bridging the two Pd2+ ions, which facilitates both methane adsorption and activation as well as the production of water and carbon dioxide during the methane oxidation process. This work highlights the sensitivity of catalytic behavior on the local structure of active sites and the fine-tuning of the metal-metal distance enabled by a support local environment for guiding the design of efficient catalysts for reactions that highly rely on Pt-group metals.
| Original language | English |
|---|---|
| Pages (from-to) | 16459-16468 |
| Number of pages | 10 |
| Journal | ACS Catalysis |
| Volume | 14 |
| Issue number | 21 |
| DOIs | |
| State | Published - Nov 1 2024 |
Funding
This research is 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. The sample preparation and reaction test were conducted as part of a user project at the Center for Nanophase Materials Sciences, which is a Department of Energy, Office of Science User Facility at Oak Ridge National Laboratory. This research used Hitachi HD2700C STEM of the Center for Functional Nanomaterials (CFN), which is a U.S. Department of Energy Office of Science User Facility, at Brookhaven National Laboratory under Contract No. DE-SC0012704. This research used Beamline 7-BM (QAS) of the National Synchrotron Light Source II, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory under Contract No. DE-SC0012704. 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. 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 |
|---|---|
| United States Government | |
| Basic Energy Sciences | |
| DOE Public Access Plan | |
| Oak Ridge National Laboratory | |
| Center for Functional Nanomaterials | |
| U.S. Department of Energy | |
| Office of Science | |
| Brookhaven National Laboratory | DE-SC0012704 |
| National Energy Research Scientific Computing Center | DE-AC05-00OR22725, DE-AC02-05CH11231 |
Keywords
- Pd single atoms
- Pd structure
- methane combustion
- tune Pd−Pd distance