Patel Ashok Raj, Patel Geetika, Maity Gurupada, Patel Shiv P, Bhattacharya Sumantra, Putta Anjaneyulu, Banerjee Subhash
Department of Chemistry, Guru Ghasidas Vishwavidyalaya, Koni, Bilaspur, C.G. 495009, India.
Department of Pure and Applied Physics, Guru Ghasidas Vishwavidyalaya, Koni, Bilaspur, C.G. 495009, India.
ACS Omega. 2020 Nov 17;5(47):30416-30424. doi: 10.1021/acsomega.0c03562. eCollection 2020 Dec 1.
Herein, we report the synthesis of a self-assembled flower-like CuCoO material by the oxalate decomposition method. The crystalline structure and morphology of the material have been analyzed by powder X-ray diffraction, Raman spectroscopy, field-emission scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray measurement techniques. The self-assembled flower-like CuCoO material showed remarkable catalytic activity in the direct aerobic oxidative azo coupling of anilines under oxidant and other additive-free reaction conditions. The mechanistic insight of CuCoO in the oxidative azo coupling reaction has been established by density functional theory calculations, which disclosed that the absorption and dissociation of areal oxygen preferentially take place at the Cu site and dissociation of aniline takes place at the Co site. Thus, the Cu and Co sites of CuCoO exert a cooperative effect on the direct oxidative azo coupling reactions through the selective activation of anilines and aerobic oxygen. The CuCoO material was recovered from the reaction mixture and reused for at least eight runs without appreciable loss of catalytic activity.
在此，我们报道了通过草酸盐分解法合成的一种自组装花状CuCoO材料。采用粉末X射线衍射、拉曼光谱、场发射扫描电子显微镜、透射电子显微镜和能量色散X射线测量技术对该材料的晶体结构和形貌进行了分析。这种自组装花状CuCoO材料在无氧化剂和其他添加剂的反应条件下，对苯胺的直接有氧氧化偶氮偶联反应表现出显著的催化活性。通过密度泛函理论计算确定了CuCoO在氧化偶氮偶联反应中的机理，结果表明，表面氧的吸附和解离优先发生在Cu位点，苯胺的解离发生在Co位点。因此，CuCoO的Cu和Co位点通过对苯胺和有氧氧的选择性活化，对直接氧化偶氮偶联反应发挥协同作用。从反应混合物中回收了CuCoO材料，并重复使用至少八次，催化活性没有明显损失。
