title: Key role of the pore volume of zeolite for selective production of propylene from olefins.
abstract: A plausible reaction mechanism for propylene (C(3)H(6)) production from ethylene (C(2)H(4)) was investigated, based on the amounts of effluent hydrocarbons and hydrocarbons produced in the pores of SAPO-34. Propylene was produced via an oligomerization-cracking mechanism. On the basis of this mechanism, the conversions of C(2)H(4), pentenes, and hexenes were examined. The catalytic performance was compared, in order to investigate the role of the pore volume of zeolites with 8-, 10-, and 12-membered rings in the selective production of C(3)H(6). The selectivity for C(3)H(6) was crucially dependent upon the pore volume of the zeolite. Highly selective production of C(3)H(6) from olefins (C(2)H(4), pentenes, and hexenes) can be accomplished by employing a new concept: adjusting the pore volume of a zeolite to accommodate the volume of an olefin and/or its carbenium cations, as opposed to a conventional molecular sieve approach. For example, an unimolecular cracking of pentenes into C(3)H(6) and C(2)H(4) involving primary cations can be controlled by the pore volume of a zeolite.
authors.affiliation: Department of Environmental Chemistry and Engineering, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502, Japan.
authors.forename: To-ru
authors.initials: TR
authors.lastname: Koyama
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Hayashi
authors.forename: Hironori
authors.initials: H
authors.lastname: Horie
authors.forename: Susumu
authors.initials: S
authors.lastname: Kawauchi
authors.forename: Akihiko
authors.initials: A
authors.lastname: Matsumoto
authors.forename: Yasuyoshi
authors.initials: Y
authors.lastname: Iwase
authors.forename: Yasuharu
authors.initials: Y
authors.lastname: Sakamoto
authors.forename: Akimitsu
authors.initials: A
authors.lastname: Miyaji
authors.forename: Ken
authors.initials: K
authors.lastname: Motokura
authors.forename: Toshihide
authors.initials: T
authors.lastname: Baba