Characterization of Catalyst Materials in the Electron and Atom Probe Microscopes
EMSL Project ID
47785
Abstract
The overall goal of this proposal is to develop a fundamental understanding of how to predict, synthesize, and control the compositions, structures, and catalytic function of supported metal clusters possessing designed atomic connectivity and ligand environments. Specifically, the PI of this proposal aims to advance the existing characterization tools at PNNL by combining several key tools in the electron and atom-probe microscopes. For example, the combination of atomic-resolution images of single or small metal cluster catalysts with 3-D electron tomography of its porous zeolite support for a complete understanding of the system connecting length and dimension scales; the combination of ex-situ or in-situ gas reduction combined with 3-D imaging to determine the 3-D distribution and morphology of the catalysts within the support before and after reduction; or the combination of electron tomography (ET) with atom probe tomography (APT) at various stages of reduction, providing the new capability of understanding the 3-D morphology, distribution, and chemistry with atomic resolution and without artifacts (the artifacts can be removed through the 3-D correlation of the ET and APT data). Electron energy loss spectroscopy (EELS) will be a major part of each set of experiments as an understanding of the changes in bonding and electronic structure is imperative to a fundamental understanding of the system as a whole. Further, it is important to characterize the structures, intermediates, and catalytic reaction products at various stages of growth and design, so not only is it essential to combine the techniques, it is also necessary to examine the materials through a “time-lapse" of various stages of design.
Project Details
Start Date
2013-02-01
End Date
2013-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Gao F, JH Kwak, J Szanyi, and CHF Peden. 2013. "Current Understanding of Cu-Exchanged Chabazite Molecular Sieves for Use as Commercial Diesel Engine DeNOx Catalysts." Topics in Catalysis 56(15-17):1441-1459. doi:10.1007/s11244-013-0145-8