高比表面积介孔SiO_2负载V-P氧化物催化乙酸-甲醛羟醛缩合制丙烯酸研究  

Preparation of acrylic acid via aldol by condensation of vapor-phase acetic acid with formaldehyde over mesoporous SiO_2 with high specific surface area supported V-P oxides

作　　者：肖熙[1,2] 袁善良 张彪 薄其飞[1] 余红伟 郑林 蒋毅[1] 

机构地区：[1]中国科学院成都有机化学研究所 [2]中国科学院大学 [3]川化集团有限公司

出　　处：《石油与天然气化工》2018年第1期41-45,59,共6页Chemical engineering of oil & gas

摘　　要：以不同孔径的高比表面积介孔SiO_2为载体,通过浸渍法制备VPO/SiO_2-x(x=6、8、10、12,平均孔径)催化剂。采用BET、XRD、XPS和NH_3-TPD对催化剂进行表征,并考察了其对甲醛-乙酸多相催化制丙烯酸的催化性能。结果表明,不同孔径VPO/SiO_2催化剂均具有较高的比表面积(>180m^2/g)和发达的介孔结构,其平均孔径分别为6.5nm、8.7nm、10.6nm和13.0nm;VPO/SiO_2上丙烯酸的催化选择性由于受催化剂孔径的影响依次为VPO/SiO_2-10>VPO/SiO_2-12>VPO/SiO_2-8>VPO/SiO_2-6。反应温度为350℃时,孔径为10.6nm的VPO/SiO_2上丙烯酸的选择性和收率分别达到76.8%和47.1%,甲醛转化率为61.2%。The VPO/SiO_2-x(=6,8,10,12,average pore size)catalysts are prepared by impregnation methods using high specific surface area SiO_2 with different pore size as supports.The catalysts are characterized by BET, XRD, XPS and NH_3-TPD, and also investigated by heterogeneous catalysis of aldol condensation of acetic acid with formaldehyde to produce acrylic acid.The results show that all catalysts have higher specific surface area(>180 m^2/g)and well-developed mesoporous structure,but with average pore size of 6.5 nm,8.7 nm,10.6 nm and 13.0 nm,respectively.The acrylic acid selectivity over the prepared VPO/SiO_2-x catalysts follow the order of VPO/SiO_2-10 > VPO/SiO_2-12 > VPO/SiO_2-8 > VPO/SiO_2-6. The catalytic conversion of formaldehyde over VPO/SiO_2-10(average pore size is 10.6 nm)reaches 61.2% when the reaction temperature is 350 ℃,with acrylic acid selectivity and yield of 76.8% and 47.1% respectively.

关 键 词：V-P氧化物 丙烯酸 甲醛 乙酸 羟醛缩合 

分 类 号：TQ225.131[化学工程—有机化工] TQ426