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首页> 外文期刊>Journal of King Saud University >Functionalized multi walled carbon nanotubes supported copper-titania nanoparticles for oxidation of cinnamyl alcohol under mild reaction conditions
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Functionalized multi walled carbon nanotubes supported copper-titania nanoparticles for oxidation of cinnamyl alcohol under mild reaction conditions

机译:官能化多壁碳纳米管支撑铜二氧化钛纳米粒子,用于在轻度反应条件下氧化肉桂醇

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ObjectivesAlcohols oxidation is one of the important organic transformation in fine chemical industries. Prevailing processes are hazardous due to involvement of stoichiometric oxidants and homogeneous catalysts. In the present work, oxidation of cinnamyl alcohol was carried out using unconventional, affordable, and feasible heterogeneous catalysts.MethodCopper-titania (Cu-Ti) nanoparticles were prepared and supported on functionalized multi walled carbon nanotubes (F-CNTs). Various instrumental techniques such as X-ray Diffractometery (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX) Analysis and Brunauer Emmett Teller (BET) surface area analyzer were used to characterize the synthesized catalysts. Both catalysts; Cu-Ti and Cu-Ti/F-CNTs were evaluated for their potencies in conversion of cinnamyl alcohol (CnOH) to cinnamaldehyde (CnHO). Different derivatives of CnOH (with attached electron withdrawing and donating groups) were also oxidized in presence of prepared catalysts to determine the substituents effect and get maximum yield. The prepared catalyst was used five times to determine its reuseablity.ResultsThe presence of copper and titania in the synthesized catalyst structure was confirmed through XRD and EDX analysis. The agglomeration level was confirmed from SEM analysis. Little reduction in surface area on parental carbon nanotubes was observed due to deposited metals. Appreciable yield of CnHO were obtained at the optimal reaction conditions: temperature?=?70?°C, catalyst amount?=?0.1?g, pO2?=?760?Torr, substrate solution concentration and volume?=?1?mmol CnOH/10?mL ethanol, stirring speed?=?900?rpm, and time interval?=?60?min. The conversion rate was improved to 100% through attachment of electron donating groups at ortho and para position of parental compound benzene ring. No appreciable decrease in activity of catalyst were observed after 4th cycle.ConclusionCu-Ti/F-CNTs showed excellent catalytic activity, selectivity, true heterogeneous nature, low cost, and recyclability, hence it could be used as a potent catalyst for CnOH to CnHO conversion.
机译:玻璃醇氧化是精细化工工业中重要的有机转化之一。由于化学计量氧化剂和均相催化剂的参与,普遍的过程是危险的。在本作本作中,使用非常规,实惠的和可行的非均相催化剂进行糖醇的氧化。制备甲基二戊二醇 - 二氧化钛(Cu-Ti)纳米颗粒并负载在官能化的多壁碳纳米管(F-CNT)上。诸如X射线衍射(XRD),扫描电子显微镜(SEM),能量分散X射线(EDX)分析和Brunauer Emmett陈列塞(BET)表面积分析仪的各种仪器技术用于表征合成催化剂。催化剂;评估Cu-Ti和Cu-Ti / F-CNT,以转化肉桂醇(CNOH)至肉桂醛(CNHO)的疗效。在制备的催化剂存在下,CNOH的不同衍生物(用连接的电子抽出和捐赠组)也被氧化,以确定取代基效应并获得最大收率。使用制备的催化剂进行五次以确定其再血化。通过XRD和EDX分析证实了合成催化剂结构中的铜和二氧化钛的存在。从SEM分析证实了凝聚水平。由于沉积的金属,观察到父母碳纳米管上的表面积的几乎没有降低。在最佳反应条件下获得CNHO的明显产量:温度α= 70℃,催化剂量?=α=0.1≤g,po2?= 760?torr,底物溶液浓度和体积?=α1≤mmol / 10?ml乙醇,搅拌速度?=Δ= 900?RPM和时间间隔?=?60?min。通过在亲本化合物苯环的邻和对位的邻位连接的电子捐赠基团附着,转化率改善为100%。在第4次循环后观察到催化剂活性的可明显降低。结论肠梗/ F-CNT,表现出优异的催化活性,选择性,真正的异质性,低成本和可回收性,因此它可以用作CNOH至CNHO的有效催化剂转换。

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