Microstructural characteristics of vehicle-aged heavy-duty diesel oxidation catalyst and natural gas three-way catalyst
Journal article, 2019

Techniques to control vehicle engine emissions have been under increasing need for development during the last few years in the more and more strictly regulated society. In this study, vehicle-aged heavy-duty catalysts from diesel and natural gas engines were analyzed using a cross-sectional electron microscopy method with both a scanning electron microscope and a transmission electron microscope. Also, additional supporting characterization methods including X-ray diffractometry, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy and catalytic performance analyses were used to reveal the ageing effects. Structural and elemental investigations were performed on these samples, and the effect of real-life ageing of the catalyst was studied in comparison with fresh catalyst samples. In the real-life use of two different catalysts, the poison penetration varied greatly depending on the engine and fuel at hand: the diesel oxidation catalyst appeared to suffer more thorough changes than the natural gas catalyst, which was affected only in the inlet part of the catalyst. The most common poison, sulphur, in the diesel oxidation catalyst was connected to cerium-rich areas. On the other hand, the severities of the ageing effects were more pronounced in the natural gas catalyst, with heavy structural changes in the washcoat and high concentrations of poisons, mainly zinc, phosphorus and silicon, on the surface of the inlet part.

Catalyst deactivation

Poisoning

SEM

Natural gas

TEM

Diesel

Author

Tomi Kanerva

Työterveyslaitos

University of Tampere

M. Honkanen

University of Tampere

T. Kolli

University of Oulu

O. Heikkinen

Aalto University

Murata Electronics Oy

Kauko Kallinen

Dinex Finland Oy

Tuomo Saarinen

SSAB AB

Sandvik Mining and Construction Oy

J. Lahtinen

Aalto University

Eva Olsson

Chalmers, Physics, Eva Olsson Group

Riitta L. Keiski

University of Oulu

M. Vippola

University of Tampere

Catalysts

2073-4344 (ISSN)

Vol. 9 2 137

Subject Categories

Chemical Process Engineering

Other Chemical Engineering

Other Chemistry Topics

DOI

10.3390/catal9020137

More information

Latest update

7/21/2019