Emission Performance of Hydrothermal Aging SCR Catalysts for China Ⅵ Diesel Engine

LIU Weilin; PANG Guomin; GUO Yachen; ZHAO Liang

doi:10.3969/j.issn.1001-2222.2024.05.005

Vehicle Engine ›› 2024, Vol. 0 ›› Issue (5) : 32. DOI: 10.3969/j.issn.1001-2222.2024.05.005

Emission Performance of Hydrothermal Aging SCR Catalysts for China Ⅵ Diesel Engine

LIU Weilin,PANG Guomin,GUO Yachen，ZHAO Liang

Author information +

History +

Abstract

In order to study the emission performance of selective catalytic reduction (SCR) catalyst used in the China Ⅵ certification demonstration test, the emission characteristics of fresh SCR catalyst and aged SCR catalyst were compared and analyzed from the aspects of nitrogen oxide (NO_x) conversion efficiency, ammonia storage performance, transient cycle emission and actual road emission through engine bench test and vehicle test. The results show that the aged SCR catalyst can be prepared through 30 h aging of the fresh SCR catalyst in air containing 10% water vapor at 850 ℃, which meets the requirements of the onboard diagnostic system (OBD) demonstration test. The adsorption capacity of aging SCR catalyst to NH₃ reduces greatly, the average NO_x conversion efficiency of transient cycle test decreases by 21.1% compared with that of the fresh catalyst, and the volume concentration of ammonia leakage is up to 304.98×10^-6which should also be paid attention to and limited as the exhaust pollutant. In terms of actual vehicle on-road emission, the NO_x aging rates of aged catalyst under different working conditions are similar and the NO_x emission of 90% decile value is 1 982.67 mg/(kW·h), which is nearly 6.31 times higher than that of fresh catalyst. The NO_x window specific emission passing rate is 0%. However, the volume concentration of more than 500×10^-6 accounts for only 0.2%, which is far lower than the China Ⅵ limit value of 5%. The subsequent upgrade of emission regulations needs to focus on the transient volume concentration of NO_x.

Key words

selective catalytic reduction / catalyst / emission performance / hydrothermal aging

Cite this article

EndNote

Ris (Procite)

Bibtex

Download Citations

LIU Weilin,PANG Guomin,GUO Yachen，ZHAO Liang. Emission Performance of Hydrothermal Aging SCR Catalysts for China Ⅵ Diesel Engine[J]. Vehicle Engine. 2024, 0(5): 32 https://doi.org/10.3969/j.issn.1001-2222.2024.05.005