A Microporous Aluminosilicate with 12-, 12-, and 8-Ring Pores and Isolated 8-Ring Channels

Journal of the American Chemical Society

5 years ago

A Microporous Aluminosilicate with 12-, 12-, and 8-Ring Pores and Isolated 8-Ring Channels

Qiao Han, Takuji Ikeda, Naoto Nakazawa, Satoshi Inagaki, Yuka Yoshida, Norihito Hiyoshi, Yoshihiro Kubota

Synthesis of new zeolites with controlled pore architectures is important in the field of catalysis and separation related to chemical transformation, environmental protection, and energy-saving. Zeolites containing channels of different sizes in the same framework have been desirable. We report here the synthesis and structure of a novel aluminosilicate zeolite (designated as YNU-5), the first zeolite containing interconnected 12-, 12-, and 8-ring pores, as well as independent straight 8-ring channels. The synthesis procedure is quite simple and consists of conventional hydrothermal conditions as well as readily available starting materials. The framework structure is stable enough and Si/Al ratio is controllable between 9 and 350. Determination of the crystal structure is performed by utilizing X-ray diffraction-based techniques, revealing 9 independent tetrahedrally coordinated atoms. This robust structure is expected to be industrially valuable and several unusual combinations of composite building units are of considerable interest in an academic sense. The new zeolite YNU-5 is promising catalyst for the production of useful light olefins such as propylene and butylenes in the dimethyl ether-to-olefin reaction, when the Si/Al ratio is properly tuned by dealumination through simple acid treatments.

Publisher URL: http://dx.doi.org/10.1021/jacs.7b03308

DOI: 10.1021/jacs.7b03308