文章基本信息

标题：Metalloenzyme-like catalyzed isomerizations of sugars by Lewis acid zeolites
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作者：Ricardo Bermejo-Deval ; Rajeev S. Assary ; Eranda Nikolla 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2012
卷号：109
期号：25
页码：9727-9732
DOI：10.1073/pnas.1206708109
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Isomerization of sugars is used in a variety of industrially relevant processes and in glycolysis. Here, we show that hydrophobic zeolite beta with framework tin or titanium Lewis acid centers isomerizes sugars, e.g., glucose, via reaction pathways that are analogous to those of metalloenzymes. Specifically, experimental and theoretical investigations reveal that glucose partitions into the zeolite in the pyranose form, ring opens to the acyclic form in the presence of the Lewis acid center, isomerizes into the acyclic form of fructose, and finally ring closes to yield the furanose product. The zeolite catalysts provide processing advantages over metalloenzymes such as an ability to work at higher temperatures and in acidic conditions that allow for the isomerization reaction to be coupled with other important conversions.
关键词：glucose isomerization ; heterogeneous catalysis ; reaction mechanism