La-SO4^2-改性SBA-15分子筛的制备、表征及催化合成乙酸正丁酯  

Preparation of SBA-15 Molecular Sieve Modified with Lanthanum-SO_4^(2-)and Its Catalytic Activity in Synthesis of n-Butyl Acetate

作　　者：田志茗[1,2] 邓启刚[2] 尹燕磊[2] 赵德丰[1] 

机构地区：[1]大连理工大学国家精细化工重点实验室,辽宁大连116012 [2]齐齐哈尔大学化学化工学院,黑龙江齐齐哈尔161006

出　　处：《石油化工》2008年第7期667-671,共5页Petrochemical Technology

摘　　要：用固体研磨法对 SBA-15分子筛进行 La-SO_4^(2-)改性,制备了 La-SO_4^(2-)改性 SBA-15分子筛(La-SO_4^(2-)/SBA-15)催化剂,采用 X 射线衍射、红外光谱和低温 N_2吸附-脱附、热重-差热分析、NH_3-程序升温脱附等方法对 La-SO_4^(2-)/SBA-15催化剂进行了表征。表征结果显示,La 已进入 SBA-15分子筛中,制得的 La-SO_4^(2-)/SBA-15催化剂保持高度有序的二维六方介孔结构。用 Hammett 指示剂法测得 La-SO_4^(2-)/SBA-15催化剂的表面酸强度(H_0)为2.77<H_0≤3.30,酸量为0.597 2 mmol/g。采用 La-SO_4^(2-)/SBA-15催化剂催化合成乙酸正丁酯,优化的合成反应条件为:n(冰乙酸):n(正丁醇)=1:1.4,催化剂用量为冰乙酸质量的7.5%,反应时间为120 min,在此条件下酯化率为90.6%。Mesoporous molecular sieve SBA-15 was synthesized and incorporated with lanthanum and sulfate group by solid state grinding without solvent. The obtained molecular sieve was characterized by means of XRD, low temperature nitrogen adsorption-desorption, IR, TG-DTA and NH3-TPD. Results showed that lanthanum had been incorporated into SBA-15 molecular sieve. The prepared La-SO4^2-/SBA-15 catalyst keeps highly ordered mesoporous two-dimensional hexagonal structure and does not change mesoporous channel structure of mother SBA-15 molecular sieve. Acid strength（H0） on catalyst surface was determined by mean of Hammett indication method（2.77 〈 H0≤ 3.30）. Amount of acid was determined to be 0. 597 2 mmol/g. La-SO4^2-/SBA-15 is an excellent catalyst for synthesis of n-butyl acetate, and can be recovered and reused. Optimum conditions of esterification are obtained by orthogonal experiments： mole ratio of acetic acid to n-butanol 1 ： 1.4, amount of La-SO4^2-/SBA-15 catalyst 7.5% mass of acetic acid, reaction time 120 min. Yield of n-butyl acetate can reach 90.6% under the optimum conditions.

关 键 词：SBA-15分子筛 镧改性 酯化反应 催化 乙酸正丁酯 

分 类 号：TQ203.2[化学工程—有机化工]