Fuel Sulfur and Aging Effects on the Oxygen Storage Capacity in Three-Way Catalytic Converters 2003-01-1874
The catalyst oxygen storage capacities were measured over a test matrix consisted of fuels with 7, 33, 266 and 500 ppm sulfur, and of dynamometer-aged catalysts simulating 4K, 50K and 150K vehicle miles. A methodology was developed to relate the post-catalyst λ sensor response following an engine lean-step-transient to the total oxygen storage sites available. The time resolved NOx concentration profiles (which were most sensitive to the oxygen storage) in the catalyst were measured with the engine operating at λ modulations of various amplitudes and frequencies. The oxygen storage capacity deterioration comprised two multiplicative factors - an age factor which decreased quickly initially (by a factor of 2 from 4K to 50K miles), and then more modestly (by 30% from 50 to 150K miles), and a fuel sulfur factor which decreased by 10% for every 150 ppm increase in sulfur level. Within reasonable ranges, the NO conversion efficiency was insensitive to the λ modulation amplitude and frequency. The degradation of NO conversion efficiency with age was attributed to the loss of precious metal sites rather than to the inadequacy of oxygen storage.
Citation: Zhang, Y. and Cheng, W., "Fuel Sulfur and Aging Effects on the Oxygen Storage Capacity in Three-Way Catalytic Converters," SAE Technical Paper 2003-01-1874, 2003, https://doi.org/10.4271/2003-01-1874. Download Citation
Author(s):
Yuetao Zhang, Wai K. Cheng
Affiliated:
Sloan Automotive Laboratory, Massachusetts Institute of Technology
Pages: 13
Event:
2003 JSAE/SAE International Spring Fuels and Lubricants Meeting
ISSN:
0148-7191
e-ISSN:
2688-3627
Also in:
Advanced Emission Aftertreatment Systems-SP-1796, SAE 2003 Transactions Journal of Fuels and Lubricants-V112-4
Related Topics:
Storage
Catalysts
Oxygen
Nitrogen oxides
Metals
Wear
SAE MOBILUS
Subscribers can view annotate, and download all of SAE's content.
Learn More »