介孔SiO_2/Al_2O_3固体酸催化γ-戊内酯脱羰基制备丁烯

Decarboxylation of γ-Valerolactone into Butenes by Mesoporous SiO_2/Al_2O_3 Solid Acid Catalyst

采用溶胶-凝胶法合成了介孔SiO2/Al2O3催化剂,用于γ-戊内酯脱羰基制丁烯,对催化剂进行了表征,考察了反应条件对丁烯生成的影响,并分析了γ-戊内酯脱羰基制丁烯的反应机理.结果表明,SiO2/Al2O3的平均吸附孔径为6.8768 nm,BET比表面积达398.4 m2/g,催化剂表面存在Lewis和Br?nsted酸位;在350℃、催化剂用量为γ-戊内酯量的5%(ω)、反应4 h的条件下,γ-戊内酯的转化率在99%以上,丁烯产率最高达97%;反应机理为,在SiO2/Al2O3作用下,γ-戊内酯先开环生成戊烯酸,戊烯酸发生α和β碳裂解生成丁烯和CO2.

Mesoporous SiO2/Al2O3 catalyst was prepared by sol-gel method and characterized by XRD, BET and pyridine-FTIR for the decarboxylation of γ-valerolactone to produce butenes. The effects of reaction conditions on the production of butenes were examined, and the decarboxylation mechanism was analyzed. The results showed that the average absorption pore size of the catalyst was 6.8768 nm and its specific surface area 398.4 m2/g, and Lewis and Br？nsted acid sites were found on its surface. The highest yield of butenes of 97% was achieved at 350℃ for 4 h with 5%（ω） catalyst. The decarboxylation mechanism was analysed as that γ-velerolactone was firstly converted to pentenoic acids by ring opening, then α and β carbons of pentenoic acid were cracked to produce butenes and CO2.