Negahdar, L., Omori, N.E., Quesne, M.G. orcid.org/0000-0001-5130-1266 et al. (6 more authors) (2021) Elucidating the Significance of Copper and Nitrate Speciation in Cu-SSZ-13 for N2O Formation during NH3‑SCR. ACS Catalysis, 11 (21). pp. 13091-13101. ISSN 2155-5435
Abstract
Unwanted N2O formation is a problem that has been noted in selective catalytic reduction (SCR) where copper zeolite catalysts are utilized. With its immense global warming potential and long-term stability, elevated atmospheric N2O has already been identified as a future challenge in the war on climate change. This paper explores the phenomenon of N2O formation during NH3-SCR over Cu-SSZ-13 catalysts, which are currently commercialized in automotive emissions control systems, and proposes a link between N2O production and the local copper environment found within the zeolite. To achieve this, a comparison is made between two Cu-SSZ-13 samples with different copper co-ordinations produced via different synthesis methods. A combination of synchrotron X-ray absorption near-edge spectroscopy, UV−vis, Raman, and density functional theory (DFT) is used to characterize the nature of copper species present within each sample. Synchrotron IR microspectroscopy is then used to compare their behavior during SCR under operando conditions and monitor the evolution of nitrate intermediates, which, along with further DFT, informs a mechanistic model for nitrate decomposition pathways. Increased N2O production is seen in the Cu-SSZ-13 sample postulated to contain a linear Cu species, providing an important correlation between the catalytic behavior of Cu-zeolites and the nature of their metal ion loading and speciation.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2021 The Authors. This is an open access article under the terms of the Creative Commons Attribution License (CC-BY-NC-ND 4.0), which permits unrestricted use, distribution and reproduction in any medium, provided the original work is properly cited. |
Keywords: | Cu-zeolites; NH3-SCR; NOx; operando IR; XAFS; DFT calculation; mechanism |
Dates: |
|
Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemistry (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 13 Sep 2024 14:31 |
Last Modified: | 13 Sep 2024 14:31 |
Status: | Published |
Publisher: | American Chemical Society |
Identification Number: | 10.1021/acscatal.1c03174 |
Sustainable Development Goals: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:217177 |