无模板法合成C_3N_4纳米片在Knoevenagel缩合反应中的应用
|
摘要
以NaCl为添加剂、三聚氰胺为原料,一步热解法合成C_3N_4纳米片(C_3N_4-S).在苯甲醛与氰乙酸乙酯的Knoevenagel缩合反应中,C_3N_4-S的催化活性明显高于未添加NaCl的普通C_3N_4.表征发现:NaCl的添加量和焙烧温度能够显著影响C_3N_4-S的比表面积和催化活性.以C_3N_4-S-550-0.863为催化剂,在70℃下反应4 h,苯甲醛的转化率达到96.8%,α-氰基肉桂酸乙酯选择性为100%.最低反应温度可低至30℃,具有良好的可重复使用性能.
C_3N_4 nano-sheet( C_3N_4-S) was synthesized by one-pot pyrolysis of mixture of melamine and NaCl. As for Knoevenagel condensation of benzaldehyde with malononitrile,C_3N_4-S exhibits much higher activity than that of NaCl-free C_3N_4. Characterization results indicate that the NaCl amount and pyrolysis temperature significantly influent the surface area and catalytic activity of C_3N_4-S. It is found that C_3N_4-S-550-0.863 affords 96.8% conversion of benzaldehyde and 100% selectivity of benzylidene malononitrile. Moreover,C_3N_4-S-550-0. 863 is recyclable and active even at 30 ℃.
C_3N_4 nano-sheet( C_3N_4-S) was synthesized by one-pot pyrolysis of mixture of melamine and NaCl. As for Knoevenagel condensation of benzaldehyde with malononitrile,C_3N_4-S exhibits much higher activity than that of NaCl-free C_3N_4. Characterization results indicate that the NaCl amount and pyrolysis temperature significantly influent the surface area and catalytic activity of C_3N_4-S. It is found that C_3N_4-S-550-0.863 affords 96.8% conversion of benzaldehyde and 100% selectivity of benzylidene malononitrile. Moreover,C_3N_4-S-550-0. 863 is recyclable and active even at 30 ℃.
引文
[1]Freeman F.Properties and reactions of ylidenemalononitriles[J].Chem Rev,1980,80(4):329-350.
[2]Xue B,Zhu J,Liu N,et al.Facile functionalization of graphene oxide with ethylenediamine as a solid base catalyst for Knoevenagel condensation reaction[J].Catal Commun,2015,64:105-109.
[3]Hasegawa T,Krishnan C K,Ogura M.Promising catalytic performance and shape-selectivity of nitrogen-doped siliceous MFI zeolite for base-catalyzed reactions[J].Micro Meso Mater,2010,132:290-295.
[4]Kubota Y,Nishizaki Y,Sugi Y.High catalytic activity of as-synthesized,ordered porous silicate-quaternary ammonium composite for Knoevenagel condensation[J].Chem Lett,2000,29:998-999.
[5]Liu X J,Wang G Y,Sun L F.Synthesis ofα-furylacrylic acid[J].Chin J Fine Chem,2001,18(7):428.
[6]Wang Y,Ren Z J,Cao W G,et al.Solid state synthesis ofα-cyanoacrylamides via Knoevenagel condensation[J].Chin J Shanghai University,2003,9(1):78.
[7]Zhang W,Liang J,Liu Y,et al.Knoevenagel condensation reaction over acid-base bifunctional Mg O/HMCM-22 catalysts[J].Chin J Catal,2013,34(3):559-566.
[8]Cao Y D,Yang C.Base catalysis researching of functionalised hexagonal mesoporous silica[J].Chin J Acta Petrol Sin,2002,18(6):20.
[9]Sharma P,Sasson Y.Highly active g-C3N4as a solid base catalyst for Knoevenagel condensation reaction under phase transfer conditions[J].RSC Adv,2017,7(41):25589-25596.
[2]Xue B,Zhu J,Liu N,et al.Facile functionalization of graphene oxide with ethylenediamine as a solid base catalyst for Knoevenagel condensation reaction[J].Catal Commun,2015,64:105-109.
[3]Hasegawa T,Krishnan C K,Ogura M.Promising catalytic performance and shape-selectivity of nitrogen-doped siliceous MFI zeolite for base-catalyzed reactions[J].Micro Meso Mater,2010,132:290-295.
[4]Kubota Y,Nishizaki Y,Sugi Y.High catalytic activity of as-synthesized,ordered porous silicate-quaternary ammonium composite for Knoevenagel condensation[J].Chem Lett,2000,29:998-999.
[5]Liu X J,Wang G Y,Sun L F.Synthesis ofα-furylacrylic acid[J].Chin J Fine Chem,2001,18(7):428.
[6]Wang Y,Ren Z J,Cao W G,et al.Solid state synthesis ofα-cyanoacrylamides via Knoevenagel condensation[J].Chin J Shanghai University,2003,9(1):78.
[7]Zhang W,Liang J,Liu Y,et al.Knoevenagel condensation reaction over acid-base bifunctional Mg O/HMCM-22 catalysts[J].Chin J Catal,2013,34(3):559-566.
[8]Cao Y D,Yang C.Base catalysis researching of functionalised hexagonal mesoporous silica[J].Chin J Acta Petrol Sin,2002,18(6):20.
[9]Sharma P,Sasson Y.Highly active g-C3N4as a solid base catalyst for Knoevenagel condensation reaction under phase transfer conditions[J].RSC Adv,2017,7(41):25589-25596.