检索规则说明:AND代表“并且”;OR代表“或者”;NOT代表“不包含”;(注意必须大写,运算符两边需空一格)
检 索 范 例 :范例一: (K=图书馆学 OR K=情报学) AND A=范并思 范例二:J=计算机应用与软件 AND (U=C++ OR U=Basic) NOT M=Visual
作 者:鄢景森[1] 艾丽梅 王强 王泽清 鄂永胜[1] 刘海彬[1] YAN Jing-Sen;AI Li-Mei;WANG Qiang;WANG Ze-Qing;E Yong-Sheng;LIU Hai-Bin(School of Biomedical & Chemical Engineering,Liaoning Institute of Scienee and Technology,Benxi,Liaoning 117004,China)
出 处:《无机化学学报》2018年第12期2179-2187,共9页Chinese Journal of Inorganic Chemistry
基 金:辽宁省科技厅自然科学资金(No.20170540475;201602404和20180550114);辽宁省博士科研资金(No.20170520417)资助项目
摘 要:采用酸化-乙醚萃取法制备了不同钒取代数目的 Keggin结构的磷钨钒杂多酸,并进一步通过离子交换法合成了磺酸功能化的杂多酸离子液体催化剂,采用核磁、元素分析、红外、紫外、X射线衍射、热重-差示扫描、电位滴定等分析手段对所得样品进行了表征,考察了所得样品对氯乙酸和正戊醇的酯化反应性能和重复使用性能。结果表明,所制备的杂多酸离子液体是一种具有温度响应特性的无定型结构化合物,仍保留Keggin结构和较高的酸强度,该催化剂在反应温度下与反应物形成一相,而反应结束温度降低后,催化剂和产物又形成两相,通过简单的倾倒法就可以快速分离催化剂和反应产物。与杂多酸以及未磺酸化的杂多酸离子液体相比,磺酸功能化的杂多酸离子液体具有更高的酯催化活性。在优化的反应条件下,[PyPS]4PW11VO40(PyPS为1-(3-磺酸基)丙基吡啶)对氯乙酸的转化率可达到97.6%,重复使用4次后转化率为91.9%,而催化剂的结构未有明显变化。A series of vanadium-substituted ternary heteropoly acids with Keggin structure were synthesized by acidification-ether extraction method. Furthermore, the heteropolyanion-based ionic liquids with functional sulfonic acid group,[PyPs]3+nPW12-nVnO40 (n=1, 2, 3), were synthesized by an ion exchange method. The products were characterized by nuclear magnetic resonance spectroscopy (NMR), element analysis, Fourier transform infrared spectrophotometry (FT-IR), UV-Vis spectrophotometry, X-ray diffraction (XRD), thermogravimetry-differential scanning calorimetry (TG-DSC) and potentiometric titration measurements. The catalytic ability and reusability of the ionic liquid catalysts were evaluated in esterification reaction of chloroacetic acid with n-pentyl alcohol. The results show that the ionic liquid catalyst was an amorphous structural compound with temperature responsive characteristics, in which Keggin structure and high acid strength of ionic liquid catalyst remain. The catalyst formed a homogeneous mixture with the reactants at the reaction temperature, but precipitated with biphase separation when the reaction ends and reaction temperature was lowered, and so could be easily separated from the products by a simple filtration. Sulfonic acid functionalized heteropolyanion-based ionic liquids exhibited higher ester catalytic activity than heteropoly acids and unsulfonated heteropolyanion-based ionic liquids. Under the optimized reaction conditions, the conversion rate of[PyPS]4PW11VO40 (PyPS is 1-(3-sulfonate) propyl pyridine) to chloroacetic acid could reach 97.6%, and the conversion rate was 91.9% after repeated reaction four times, but the structure of the catalyst had no change significantly.
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在链接到云南高校图书馆文献保障联盟下载...
云南高校图书馆联盟文献共享服务平台 版权所有©
您的IP:216.73.216.41