Efficient formation of nitriles in the vapor-phase catalytic dehydration of aldoximes

Efficient formation of nitriles in the vapor-phase catalytic dehydration of aldoximes

Green Chem., 2016, Advance Article
DOI: 10.1039/C6GC00384B, Paper

Daolai Sun, Eisyun Kitamura, Yasuhiro Yamada, Satoshi Sato
Nitriles were efficiently produced in a vapor-phase dehydration of aldoximes over SiO₂ catalysts without external heat supply.

http://pubs.rsc.org/en/Content/ArticleLanding/2016/GC/C6GC00384B?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

 

A vapor-phase dehydration of acetaldoxime to acetonitrile was investigated over various solid catalysts. Among the tested catalysts, ZrO₂, Al₂O₃ and SiO₂ showed high catalytic activity for the formation of acetonitrile from acetaldoxime, while the correlation between catalytic activity and the acid property of the catalysts was not observed. Weak acidic sites such as silanols sufficiently work as catalytic sites for the dehydration, which does not require strong acids such as zeolites. Several SiO₂ catalysts with different physical properties were tested, and the SiO₂with the smallest pore size and the highest specific surface area showed the highest catalytic activity for the formation of acetonitrile. Because the dehydration of acetaldoxime to acetonitrile is exothermic, a large amount of reaction heat was generated during the reaction, and the reaction temperature was found to be significantly affected by the feed rate of the reactant and the flow rate of the carrier gas. In order to effectively utilize the in situ generated reaction heat, the dehydration of acetaldoxime to acetonitrile without using the external heat supply was conducted. The temperature was controllable even in the absence of the external heat, and the acetonitrile yield higher than 90% could be achieved in such a green operation under the environment-friendly adiabatic conditions.

 

 

Efficient formation of nitriles in the vapor-phase catalytic dehydration of aldoximes

Daolai Sun,^a   Eisyun Kitamura,^a   Yasuhiro Yamada^a and  Satoshi Sato*^a  

*Corresponding authors

^aGraduate School of Engineering, Chiba University, Chiba, Japan
E-mail: satoshi@faculty.chiba-u.jp
Fax: +81 43 290 3401
Tel: +81 43 290 3377

Green Chem., 2016, Advance Article

DOI: 10.1039/C6GC00384B

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