摘要
以全硅介孔分子筛H-KIT-1为载体,异丙醇铝为铝源,通过后合成法制备出不同铝含量的Al-KIT-1介孔分子筛,用XRD、低温N_(2)吸附-脱附、^(27)Al MAS NMR、TG-DTG对样品的结构和铝的存在形式进行了表征,用常温下吸附氨测量了表面酸量,并用对苯二酚与叔丁醇的烷基化反应评价样品的催化活性。实验结果表明:样品Al-KIT-1仍保留母体H-KIT-1的介孔结构特征,且铝大多以骨架四面体铝的形式存在。样品的催化活性不仅与其表面酸量有关,而且还与其比表面积和孔容有关。样品Al-KIT-1(20)具有规整的介孔结构,其比表面积和孔容较大,表面酸量较高,表现出最好的催化性能,在150℃下反应4 h,对苯二酚的转化率为78.9%,产物2-叔丁基-1,4-苯二酚和2,6-二叔丁基-1,4-苯二酚的得率分别为9.3%和74.7%。
A series of Al-KIT-1 mesoporous molecular sieve samples with different Al amounts were successfully prepared by post-synthesis using aluminum isopropoxide as Al source and mesoporous H-KIT-1 as support. The structure of the samples and the form of Al were characterized by XRD, low temperature N_(2) adsorption-desorption,^(27)Al MAS NMR, and DG-DTG. The acidity of the sample was measured by means of NH3adsorption. The catalytic activity of the samples was evaluated by the alkylation of hydroquinone with tert-butanol. The results show that Al-KIT-1 samples still keep the original mesoporous structures of the matrix H-KIT-1.27Al MAS NMR spectra indicate that most of Al atoms exist in framework tetrahedral aluminum, which may act as active sites for alkylation. The activity of the catalysts is not only associated with the acidity, but also related to their surface area and pore volume. The Al-KIT-1(20) sample has regular mesoporous structure, higher surface area and pore volume, and a higher amount of surface acidic sites, thus exhibiting the best catalytic performance. The conversion of hydroquinone on Al-KIT-1(20) is 78.9%. The yield of 2-tert-butyl-1,4-hydroquinone and 2,6-di-tert-butyl-1,4-hydroquinone reach 9.3% and 74.7%, respectively, after reaction at 150 ℃ for 4 h.
作者
陈佳佳
李惠云
CHEN Jiajia;LI Huiyun(College of Chemistry and Chemical Engineering,Anyang Normal College,Anyang He'nan 455002,China)
出处
《复旦学报（自然科学版）》
CAS
CSCD
北大核心
2022年第6期786-790,798,共6页
Journal of Fudan University：Natural Science
