摘要
通过水杨醛和有机二胺进行缩合反应制得Schiff碱,并在90℃浓硫酸中进行磺化反应,合成磺化Schiff碱。利用阴离子交换法,使磺化Schiff碱插入到苯甲酸根插层镁铝水滑石层间,并与Cu2+配合,制得磺化Schiff碱合铜插层类水滑石。运用X射线衍射、傅里叶变换红外光谱、氮气吸附-脱附和扫描电子显微镜等进行表征,并应用于甘油的催化氧化反应。结果表明:磺化Schiff碱的分子结构明显影响甘油氧化的催化性能,以乙二胺为原料,制备的磺化Schiff碱合铜插层类水滑石催化性能最佳。磺化Schiff碱的配合中心的过渡金属是催化剂的活性位点,Cu2+表现出最佳的催化性能。NaOH的用量和反应温度明显影响甘油转化率和甘油酸选择性。反应最佳条件为:反应温度60℃,n(NaOH)∶n(甘油)物质的量比为8∶1,氧气流速为80mL/min,反应8h,甘油转化率为82.5%,甘油酸选择性可达46.9%。
The sulfonated Schiff base was synthesized by condensation of salicylic aldehyde and organic di- amine and then sulfonated with sulfuric acid at 90 ℃. The sulfonated Schiff base was inserted into the lay- er of hydrotalcite containing benzoic acid anion by anion ion exchange, and complexated with Cu2＋. The sulfonated Schiff base intercalated hydrotalcite was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption-desorption and scanning electron microscopy, and applied to the selective oxidation of glycerol. The structure of the sulfonated Schiff base obviously affected the catalytic performance. The sulfonated Schiff base prepared from ethylene diamine gave the best catalytic performance. The transition metal in the complex center of the catalyst was the catalytic active site, and Cu2＋showed better catalytic activity than other metals, The catalytic performence was obviously affected by the using amount of NaOH and reaction temperature. The optimum reaction conditions were as follows：60 ℃, NaOH to glycerol molar ratio of 8, oxygen 80 mL/min and reaction time 8 h. The glycerol conversion was 82.5 %, selectivity of and the glyceric acid was 46.9%.
出处
《化学世界》
CAS
CSCD
2016年第9期573-578,共6页
Chemical World
