Abstract
The Pd-Zn γ-brass phase provides exciting opportunities for synthesizing site-isolated catalysts with precisely controlled Pd active site ensembles. Introducing a third metallic element into the γ-brass lattice further perturbs the catalytic active site ensembles. Here, we introduce coinage metallic elements M (M = Cu, Ag, and Au) into the Pd-Zn γ-brass phase and investigate the site occupation factors of each element in the γ-brass lattice. The CALculation of PHAse Diagrams (CALPHAD) modeling approach supported by energetics predicted by the density functional theory and X-ray and neutron diffraction with Rietveld refinement were used to identify the SOF on each Wyckoff site for various M amounts alloyed into the Pd-Zn γ-brass phase. The present analysis unveils the strong preference for Pd occupying the outer tetrahedral (OT) site in the γ-brass lattice, while the coinage metallic elements tend to substitute for Zn on the octahedral (OH) site. The determination of site occupancy in the bulk M-Pd-Zn γ-brass phase provides opportunities to investigate and tailor potential catalytically active site ensembles in the γ-brass phase materials.
| Original language | English |
|---|---|
| Pages (from-to) | 1690-1701 |
| Number of pages | 12 |
| Journal | Inorganic Chemistry |
| Volume | 64 |
| Issue number | 4 |
| DOIs | |
| State | Published - Feb 3 2025 |
| Externally published | Yes |
Funding
The authors acknowledge the financial support by the Department of Energy (DOE) via Award No. DE-SC0020147. First-principles calculations were performed partially on the Roar supercomputer at the Pennsylvania State University’s Institute for Computational and Data Sciences (ICDS), partially on the resources of the National Energy Research Scientific Computing Center (NERSC) supported by the U.S. DOE Office of Science User Facility operated under Contract No. DE-AC02-05CH11231, and partially on the Bridges resource at Pittsburgh Supercomputing Center through allocation CTS150057 from the Advanced Cyberinfrastructure Coordination Ecosystem: Services & Support (ACCESS) program, which is supported by National Science Foundation grants #2138259, #2138286, #2138307, #2137603, and #2138296. A portion of this research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. The beam time was allocated to Powgen on proposal numbers IPTS-10872 and 21204.