摘要
利用"记忆效应"将氟离子插层到镁-铝水滑石的层间,并以此为前驱体焙烧制备出氟改性的镁-铝复合氧化物。采用电感耦合等离子体原子发射光谱、N2吸附-脱附技术、X射线固体粉末衍射、傅里叶变换红外光谱和Hammett指示剂法对其进行了表征。结果表明,焙烧温度明显影响样品的结构和碱性。在催化大豆油和甲醇酯交换制备生物柴油的反应中,氟改性镁-铝氧化物比纯镁-铝氧化物表现出了更优的催化性能;而且氟改性镁-铝氧化物的碱强度对其催化性能有较大影响,450℃下焙烧所得样品的催化性能最好。在催化剂用量3.0%、反应温度60℃、n(甲醇)/n(大豆油)为6、反应时间6 h的适宜条件下,大豆油和甲醇酯交换反应转化率为97.3%。
Fluorine anions were intercalated into the interlayers of Mg-Al hydrotalcites by ＂memory effect＂.The obtained fluorine-intercalated Mg-Al hydrotalcites then calcined under different temperatures to prepare the fluorine-modified Mg-Al mixed oxides.The resulted samples were characterized by various physico-chemical measurements,such as inductively coupled plasma atomic emission spectrometer,nitrogen adsorption-desorption technique,powder X-ray diffraction,Fourier transform infrared spectroscopy and Hammett indicator.The results showed that the base and structure of samples were affected by calcination temperature.Fluorine-modified Mg-Al mixed oxides were effective catalysts in the preparation of biodiesel by transesterification of soybean oil and methanol,which all exhibited much better catalytic performance than the pure Mg-Al mixed oxides.Simultaneously,the catalytic performance of fluorine-modified Mg-Al mixed oxides was closely correlated with their basic strength,and the fluorine-modified Mg-Al mixed oxide calcined at 450℃ exhibited the best catalytic performance.Under the optimal reaction conditions,which were the methanol to soybean oil molar ratio of 6,the reaction temperature of 60℃,the reaction time of 6 h and the catalyst amount of 3.0%,the reaction conversion of soybean oil and methanol transesterification could reach 97.3%.
出处
《石油学报（石油加工）》
EI
CAS
CSCD
北大核心
2011年第1期54-61,共8页
Acta Petrolei Sinica(Petroleum Processing Section)
基金
国家自然科学基金(21003073)
江苏省青蓝工程基金
南京工程学院创新基金项目资助
