Acidic properties of sulfonic acid-functionalized FSM-16 mesoporous silica and its catalytic efficiency for acetalization of carbonyl compounds
Acidic properties of sulfonic acid-functionalized FSM-16 mesoporous silica and its catalytic efficiency for acetalization of carbonyl compounds
复制标题
DOI：
10.1016/j.jcat.2005.01.017
复制
发表时间：
2005-04
影响因子：
7.3
通讯作者：
Ken-ichi Shimizu;Eidai Hayashi;Tsuyoshi Hatamachi;T. Kodama;T. Higuchi;A. Satsuma;Y. Kitayama
中科院分区：
文献类型：
--
作者：
Ken-ichi Shimizu;Eidai Hayashi;Tsuyoshi Hatamachi;T. Kodama;T. Higuchi;A. Satsuma;Y. Kitayama
采用常规的后处理方法制备了丙磺酸功能化的FSM-16介孔二氧化硅(SO3H-FSM)。与沸石、蒙脱石K10粘土、硅铝和磺酸树脂等传统的多相固体酸相比，SO3H-FSM对乙二醇缩甲醛具有更高的反应速率和1，3-二氧戊烷的产率。SO3H-FSM在反应过程中是稳定的，不存在磺酸基团的淋溶和失活，并且可以重复使用而不损失其活性。用NH3吸附、NH3-TPD和H2O-TPD的微量热法表征了SO3H-FSM的酸性和亲水性，并与各种铝硅酸盐沸石(HZSM5、HBEA、HY)和K10粘土的结果进行了比较。结果表明，SO_3-FSM的酸性不适合用NH_3-TPD表征，因为SO_3-FSM上SOH基团的分解始于200 °C以上。150 °C下的NH_3吸附微量热实验表明，与HZSM_5相比，SO_3-FSM具有较少的酸性中心，但具有相似的强酸中心，氨吸附热大于140kJ −_1。结构性质和催化性能的比较表明，要获得高活性，需要大孔径和低亲水性。具有较强酸强度的Brnsted酸中心更适合于该反应，但不是必须的高酸浓度。SO3H-FSM的高活性是由于中孔中存在较强的亲水性较低的Brnsted酸中心，两种反应物都可以顺利地接近酸性中心。
Propyl-sulfonic acid-functionalized FSM-16 mesoporous silica (SO3H-FSM) is prepared by a conventional post-modification method. For the acetalization of carbonyl compounds with ethylene glycol, SO3H-FSM shows a higher rate and 1,3-dioxolane yield than conventional heterogeneous solid acids such as zeolites, montmorillonite K10 clay, silica-alumina, and the sulfonic resin. SO3H-FSM is stable during the reaction, with no leaching and deactivation of sulfonic acid groups, and is reusable without loss of its activity. The acidity and hydrophilicity of SO3H-FSM are well characterized by the microcalorimetry of NH3adsorption, NH3-TPD, and H2O-TPD, and the result is compared with those for various aluminosilicate zeolites (HZSM5, HBEA, HY) and K10 clay. It is found that NH3-TPD is not suitable for characterizing the acidity of SO3H-FSM, because the decomposition of SO3H groups on SO3H-FSM begins above 200 °C. An NH3adsorption microcalorimetric experiment at 150 °C shows that, compared with HZSM5, SO3H-FSM has a smaller number of acid sites but has a similar number of strong acid sites with ammonia adsorption heat above 140 kJ mol−1. Comparison of the structural properties and catalytic results shows that a large pore diameter and low hydrophilicity are required to obtain high activity. Brønsted acid sites with a relatively strong acid strength are more suitable for this reaction, but the high acid concentration is not indispensable. The high activity of SO3H-FSM should be caused by the presence of the strong Brønsted acid sites in the mesopore with a relatively low hydrophilicity, where both reactants can smoothly access the acid sites.