Novel Structured Low-Temperature Oxidation Catalysts for Future Emission Control Applications
Eleni Kyriakidou, University at Buffalo
Chih-Han Liu1, Junjie Chen1, Todd J. Toops2, Cyril Thomas3, Michael J. Lance2, Stephen Porter4, Hien Pham4, Eric J. Peterson4, Abhaya K. Datye4, Jae-Soon Choi2, Zhenglong Li2, Eleni A. Kyriakidou1,*
1Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, NY 14260, USA
2Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
3Sorbonne Université, CNRS, Laboratoire de Réactivité de Surface (LRS), 4 Place Jussieu, F-75252 Paris, France
4Department of Chemical and Biological Engineering and Center for Micro-Engineered Materials, University of New Mexico, Albuquerque, NM, 87131, USA
*elenikyr@buffalo.edu
Vehicle aftertreatment systems, including diesel oxidation catalysts (DOCs) and three-way catalysts (TWCs), have been successful in reducing diesel/gasoline vehicle emissions (CO, NOx, and hydrocarbons) in the past decades. However, with the continued improvements in engine efficiency (lower emission temperatures) and more stringent emission regulations, future aftertreatment systems require an improved activity at low emission temperatures and durability in a prolonged lifetime. Rational catalyst design is essential to tackle those challenges. Metal oxide supports such as ZrO2 and CeO2 are widely used in the automotive industry to promote catalytic activity. However, both ZrO2 and CeO2 suffer from severe deactivation due to their grain growth at elevated temperatures. Herein, ZrO2 is incorporated on SiO2 and CeO2 spheres forming a ZrO2 layer with varying thickness and CeO2 nanocrystals are deposited onto penta-site rich Al2O3 nanosheets. Novel structured DOCs, TWCs catalysts, such as Pd/SiO2@Zr,1 bimetallic PdPt/SiO2@Zr, Pt/CeO2@ZrO2, and Pt/CeO2-Al2O3 nanosheet catalysts are developed and their catalytic performance (low-temperature activity and hydrothermal stability) compared to state-of-the-art catalysts is explored.2 The impact of the catalyst support/active metal compositions, local catalyst structure designs, aging conditions on low-temperature oxidation activity and hydrothermal stability will be discussed.
References
[1] E. A. Kyriakidou, T. J. Toops, J.-S. Choi, M. J. Lance, J. E. Parks, J. E., II Exhaust Treatment Catalysts with Enhanced Hydrothermal Stability and Low-Temperature Activity. US10,427,137 (October 1, 2019)
[2] Aftertreatment Protocols for Catalyst Characterization and Performance Evaluation: Low-Temperature Oxidation Catalyst Test Protocol: https://cleers.org/wp-content/uploads/2015_LTAT-Oxidation-Catalyst-Characterization-Protocol.pdf
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