Study of Mordenite ZSM-5 and NaY Zeolites,Containing Cr, Cs, Zn, Ni, Co, Li, Mn, to Control Hydrocarbon Cold-Start Emission
The implementation of Super-Ultra Low Emission
Vehicle standards requires more efficient exhaust gas purification. To
increase the efficiency of exhaust gas purification, an the adsorbent
capable of holding hydrocarbons up to 250-300 ОС should be
developed. The possibility to design such adsorbents by modification
of zeolites of mordenite type, ZSM-5 and NaY, using different
metals cations has been studied.
It has been shown that introducing Cr, Cs, Zn, Ni, Co, Li, Mn in
zeolites results in modification of the toluene TPD and toluene
5%LiZSM-5 zeolite exhibits the most attractive TPD curve, with
toluene desorption temperature ranging from 250 to 350ОС. The
sorption capacity of 5%Li-ZSM-5 is 0.4 mmol/g. NaY zeolite has the
highest sorption capacity, up to 2 mmol/g, and holds toluene up to
350ОС, but at 120ОС toluene desorption starts, which is not desirable,
since the adsorbent of cold start hydrocarbons should retain them
until 250-300ОС. Therefore 5%LiZSM-5 zeolite was found to be the
most promising to control the cold-start hydrocarbon emissions
among the samples studied.
 Absorbent-catalyst containing exhaust gas treatment device, Euro Patent
0737505, US Patent 5510086, General Motors Corp (US).
 Exhaust gas purification method and apparatus therefore, EU Patent
EP0948987 (A1), ABE FUMIO, SUZUKI JUNICHI, OGAWA
MASATO, Japan, 13.10.1999
 Cold start exhaust gas purifying catalyst, EU Patent EP1121981,
Yamamoto, Shinji (1-44-15), Koyabe, Yokosuka-shi, Kanagawa-ken,
 Exhaust gas purification device in variable combination of absorbent and
catalyst according to gas temperature, EU Patent EP0424966, Minami,
Takashi (JP), Nagase, Toshimi (JP), 05.02.1991
 J.-H. Park, S. J. Park, H. A. Ahn, I.-S. Nama, G. K. Yeo, J. K. Kil, Y. K.
Youn, "Promissing zeolite-type hydrocarbon trap catalyst by a
knowledge-based combinatorial approach," Microporous and
Mesoporous Materials, no 117, pp. 178-184, 2000.
 S.P. Elangovan, Masaru Ogura, Mark E. Davis, Tasuya Okubo, "A
Promising Material for Use as Hydrocarbon Trap," The Journal of
Physical Chemistry, B, vol. 108, no. 35, pp. 13059-13061, 2004.
 A. Iliyas, M.N. Zahedi-Niaki, M.Eić, S.Kaliaguine, "Control of
hydrocarbon cold-start emissions: A search for potential adsorbents,"
Micropous and Mesoporous Materials, no.102, pp.171-177, 2007.