Cycloaddition of Biomass-Derived Furans for Catalytic Production of Renewable p-Xylene
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- 作者：C. Luke Williams ; Chun-Chih Chang ; Phuong Do ; Nima Nikbin ; Stavros Caratzoulas ; Dionisios G. Vlachos ; Raul F. Lobo ; Wei Fan ; Paul J. Dauenhauer
- 刊名：ACS Catalysis
- 出版年：2012
- 出版时间：June 1, 2012
- 年：2012
- 卷：2
- 期：6
- 页码：935-939
- 全文大小：271K
- 年卷期：v.2,no.6(June 1, 2012)
- ISSN：2155-5435
文摘
A renewable route to p-xylene from biomass-derived dimethylfuran and ethylene is investigated with zeolite catalysts. Cycloaddition of ethylene and 2,5-dimethylfuran and subsequent dehydration to p-xylene has been achieved with 75% selectivity using H鈥揧 zeolite and an aliphatic solvent at 300 掳C. Competitive side reactions include hydrolysis of dimethylfuran to 2,5-hexanedione, alkylation of p-xylene, and polymerization of 2,5-hexanedione. The observed reaction rates and computed energy barriers are consistent with a two-step reaction that proceeds through a bicyclic adduct prior to dehydration to p-xylene. Cycloaddition of ethylene and dimethylfuran occurs without a catalytic active site, but the reaction is promoted by confinement within microporous materials. The presence of Br酶nsted acid sites catalyzes dehydration of the Diels鈥揂lder cycloadduct (to produce p-xylene and water), and this ultimately causes the rate-determining step to be the initial cycloaddition.