介孔类石墨氮化碳的制备及其催化Knoevenagel缩合反应

Mesoporous Graphitic Carbon Nitride:Synthesis and Application towards Knoevenagel Condensation Reactions

以氰胺为前驱体,通过胶态纳米氧化硅小球模板法,制备了一系列介孔类石墨氮化碳材料(mpg-C3N4)。通过X射线衍射、N2吸附-脱附、透射电镜、红外光谱、元素分析等手段对mpg-C3N4的结构和形貌等理化性质进行了表征。结果发现,通过调控硬模板和前驱体的用量可以获得比表面(190～301m2/g)和孔体积(0.65～1.07cm3/g)可调的mpg-C3N4材料。以Knoevenagel缩合为探针反应研究了mpg-C3N4的催化性能,结果显示,在以苯甲醛和丙二腈为底物的缩合反应中,去质子化mpg-C3N4表现出良好的催化性能。经简单分离后催化剂可重复使用5次以上且活性基本保持不变。

A series of mesoporous graphitic carbon nitride materials （mpg-C3 N4） had been synthesized using cyanamide as precursor and colloidal SiO2 nanosphere as template through nanocasting method. The physicochemical properties of the synthesized samples were characterized by X-ray diffraction, N2 adsorption-desorption, TEM, FT IR and elemental analysis. The profiles demonstrated that the surface areas （190 - 301m^2/g） as well as pore volumes （0.65- 1.07cm^2/g） of the materials can be tuned by varying the amount of the templates. For Knoevenagel condensation reactions exemplified by benzaldehyde and malononitrile, deprotonated mpg-C3N4, i.e. mpg-C3N4-OH exhibited excellent catalytic performance. Furthermore, the consecutive running tests indicated that the catalyst could be reused for as many as five times without appreciable loss of catalytic activity.