コンノ　ヒロキ   Konno Hiroki   今野　大輝    所属   東邦大学  理学部 生命圏環境科学科    職種   准教授
論文種別	原著
言語種別
査読の有無	査読あり
表題	Selective synthesis for light olefins from acetone over ZSM-5 zeolites with nano- and macro-crystal sizes
掲載誌名	正式名：Applied Catalysis A: General ISSNコード：0926-860X
巻・号・頁	403(1-2),183-191頁
著者・共著者	Teruoki Tago,Hiroki Konno,Mariko Sakamoto,Yuta Nakasaka,Takao Masuda
発行年月	2011/08/22
概要	Production of light olefins such as ethylene, propylene and isobutylene from acetone was examined over ZSM-5 zeolites. These light olefins are produced from acetone over the acid sites of the zeolite via a series of consecutive reactions where olefins such as ethylene and propylene are obtained by cracking of isobutylene produced from aldol condensation products of acetone. Macro- and nano-sized ZSM-5 zeolites were prepared by conventional hydrothermal and emulsion methods, respectively, and the ZSM-5 zeolites with nearly the same acidity and BET surface area were obtained regardless of the crystal sizes. From SEM observations, the crystal sizes of the zeolites were approximately 2000 nm and 30-40 nm. These zeolites with different crystal sizes were applied to light olefins synthesis from acetone, and the effect of crystal size on catalytic activity and stability was investigated. As compared with the macro-seized zeolite, the nano-sized zeolite exhibited a high activity over a long lifetime. However, because the nano-sized zeolite possesses a large external surface area, undesirable reactions to form aromatics from the produced light olefins occurred on the acid sites located near the external surface. To inhibit aromatics formation, selective deactivation of the acid sites located near the outer surface of the zeolite was achieved via the catalytic cracking of silane (CCS) method using diphenyl silane (DP-silane). The CCS method was effective in deactivating the acid sites located near the external surface of the ZSM-5 zeolite. Moreover, the nano-size zeolite after the CCS treatment using DP-silane exhibited high olefins and low aromatics yields under high acetone conversion conditions. © 2011 Elsevier B.V. All rights reserved.
DOI	10.1016/j.apcata.2011.06.029