The Impact of Lanthanum and Zeolite Structure on Hydrocarbon Storage

Catalysts

Rasmus Jonsson¹  Aiyong Wang¹  Magnus Skoglundh¹  Louise Olsson¹  PhuocHoang Ho¹ 

[1] Competence Centre for Catalysis, Chalmers University of Technology, SE-412 96 Göteborg, Sweden;

关键词: HC trap;    cold start;    toluene;    gasoline;    zeolite;    lanthanum;   

DOI  :  10.3390/catal11050635

来源: DOAJ

【 摘 要 】

Hydrocarbon traps can be used to bridge the temperature gap from the cold start of a vehicle until the exhaust after-treatment catalyst has reached its operating temperature. In this work, we investigate the effect of zeolite structure (ZSM-5, BEA, SSZ-13) and the effect of La addition to H-BEA and H-ZSM-5 on the hydrocarbon storage capacity by temperature-programmed desorption and DRIFT spectroscopy. The results show that the presence of La has a significant effect on the adsorption characteristics of toluene on the BEA-supported La materials. A low loading of La onto zeolite BEA (2% La-BEA) improves not only the toluene adsorption capacity but also the retention of toluene. However, a higher loading of La results in a decrease in the adsorbed amount of toluene, which likely is due to partial blocking of the pore of the support. High loadings of La in BEA result in a contraction of the unit cell of the zeolite as evidenced by XRD. A synergetic effect of having simultaneously different types of hydrocarbons (toluene, propene, and propane) in the feed is found for samples containing ZSM-5, where the desorption temperature of propane increases, and the quantity that desorbed increases by a factor of four. This is found to be due to the interaction between toluene and propane inside the structure of the zeolite.

【 授权许可】

Unknown