Acid-base bifunctional SBA-15 as an active and selective catalyst for synthesis of ethyl α-cyanocinnamate via Knoevenagel condensation
Acid-base bifunctional SBA-15 as an active and selective catalyst for synthesis of ethyl α-cyanocinnamate via Knoevenagel condensation
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DOI：
10.1016/j.micromeso.2021.111091
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发表时间：
2021-04
影响因子：
5.2
通讯作者：
J. N. Appaturi;Thiruchelvi Pulingam;J. Rajabathar;F. Khoerunnisa;T. Ling;S. Tan;E. Ng
中科院分区：
文献类型：
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作者：
J. N. Appaturi;Thiruchelvi Pulingam;J. Rajabathar;F. Khoerunnisa;T. Ling;S. Tan;E. Ng
报道了丙氨酸功能化介孔SBA-15（SBA-15-Alanine）对苯甲醛和氰乙酸乙酯的Knoevenagel缩合反应的催化活性和选择性。该催化剂通过使用（3-氯丙基）三乙氧基硅烷（CPTES）然后使用dl-丙氨酸的两步接枝方法制备。XRD、TEM和N2吸附结果表明，改性后的SBA-15-Alanine保持了介孔的特征。此外，IR，TG/DTG，CHN和TPD分析表明丙氨酸成功地进行了功能化，从而形成了同时具有酸性（-COOH）和碱性（-NH）中心的双功能介孔催化剂。该催化剂在非微波瞬时加热条件下，对苯甲醛与氰基乙酸乙酯的Knoevenagel缩合反应具有良好的催化性能，转化率为96.7%，α-氰基肉桂酸乙酯的选择性为100%。SBA-15-丙氨酸还显示出稳定的催化性能，具有高的可重复使用性，其中在连续五个循环后观察到催化反应性的不显著下降，从而表明在缩合反应中有希望替代碱催化剂。
Alanine functionalized mesoporous SBA-15 (SBA-15-Alanine) as an active and selective catalyst for Knoevenagel condensation reaction of benzaldehyde and ethyl cyanoacetate is reported. The catalyst is prepared by 2-step grafting approach using (3-chloropropyl)triethoxysilane (CPTES) followed bydl-alanine. The XRD, TEM and N2adsorption results reveal that the mesoporous characteristic of SBA-15-Alanine is retained upon modification. Furthermore, the IR, TG/DTG, CHN and TPD analyses indicate the successful functionalization of alanine, leading to the formation of bifunctional mesoporous catalyst bearing both acidic (-COOH) and basic (-NH) sites. This catalyst exhibits acid-base cooperative effect and good catalytic performance in the Knoevenagel condensation between benzaldehyde with ethyl cyanoacetate (96.7% conversion) with 100% selective to ethyl α-cyanocinnamate under novel non-microwave instant heating conditions. The SBA-15-Alanine also shows stable catalytic performance with high reusability where insignificant decline in catalytic reactivity is observed after five successive cycles, thus suggesting a promising replacement of base catalysts in condensation reactions.