Operando XAFS investigation on the effect of ash deposition on three-way catalyst used in Gasoline Particulate Filters and the effect of the manufacturing process on the catalytic activity

Panchal, M. et al. (2021) Operando XAFS investigation on the effect of ash deposition on three-way catalyst used in Gasoline Particulate Filters and the effect of the manufacturing process on the catalytic activity. Journal of Physics: Condensed Matter, 33(28), 284001. (doi: 10.1088/1361-648X/abfe16) (PMID:33949972)

Abstract

Platinum group metals (PGM) such as palladium and rhodium based catalysts are currently being implemented in Gasoline Particulate Filter (GPF) autoexhaust aftertreatment systems. However, little is known about how the trapped particulate matter, such as the incombustible ash, interacts with the catalyst and so may affect its performance. This operando study follows the evolution of the Pd found in two different model GPF systems: one containing ash components extracted from a GPF and another from a catalyst washcoat prior to adhesion onto the GPF. We show that the catalytic activity of the two systems vary when compared with a 0 g ash containing GPF. Compared to the 0 g ash sample the 20 g ash containing sample had a higher CO light off temperature, in addition, an oscillation profile for CO, CO2 and O2 was observed, which is speculated to be a combination of CO oxidation, C deposition via a Boudouard Reaction and further partial oxidation of the deposited species to CO. During the ageing procedure the washcoat sample reduces NO at a lower temperature than the 0 g ash sample. However, post ageing the 0 g ash sample recovers and both samples reduce NO at 310 circleC. In comparison, the 20 g ash GPF sample maintains a higher NO reduction temperature of 410 circleC post ageing, implying that the combination of high temperature ageing and presence of ash has an irreversible negative effect on catalyst performance.

• Item Type: Articles
• Additional Information: The authors would like to thank Diamond Light Source for provision of beamtime SP24156, the UK Catalysis Hub access to equipment. EPSRC (EP/R512138/1) for the iCASE studentship for M. Panchal. Johnson Matthey for the studentship and providing the GPF materials for Monik Panchal. Lara Kabalan is thanked for communicating the results of DFT calculations prior to publication. Support from the UK Catalysis Hub (EP/R026939/1, EP/R026815/1) is gratefully acknowledged.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Skukauskas, Vainius and Gibson, Dr Emma
• Authors: Panchal, M., Callison, J., Skukauskas, V., Gianolio, D., Cibin, G., York, A. P.E., Schuster, M. E., Hyde, T. I., Collier, P., Catlow, C. R. A., and Gibson, E. K.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Journal of Physics: Condensed Matter
• Publisher: IOP Publishing
• ISSN: 0953-8984
• ISSN (Online): 1361-648X
• Published Online: 05 May 2021
• Copyright Holders: Copyright © 2021 The Authors
• First Published: First published in Journal of Physics: Condensed Matter 33(28): 284001
• Publisher Policy: Reproduced under a Creative Commons License