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:李晓红[1] 尤欣[2] 梁长海[1] 张遂之[1] 魏昭彬[1] 李绪渊 李灿[1]
机构地区:[1]中国科学院大连化学物理研究所催化基础国家重点实验室,大连116023 [2]兰州大学化学系,兰州73000
出 处:《高等学校化学学报》2000年第12期1900-1903,共4页Chemical Journal of Chinese Universities
基 金:国家自然科学基金! (批准号 :2 962 5 3 0 5 )资助
摘 要:采用固定床反应器对辛可尼定修饰的 Pt/γ-Al2 O3 催化剂上丙酮酸乙酯的多相不对称加氢体系进行了研究 ,同时用高压釜反应器进行了对比 ,分别取得 60 %和 90 %的 e.e.值 .在两种不同的反应器中 ,溶剂对反应结果的影响不同 ,在高压釜反应器中乙酸的效果好于乙醇 ,而在固定床反应器中则相反 ,推测在固定床反应器中催化表面反应机理与所用溶剂的介电常数或其极性有关 .以 CO探针分子对辛可尼定在催化剂表面的吸附行为进行了红外光谱研究 。The enantioselective hydrogenation of ethyl pyruvate on the cinchonidine modified Pt/Al 2O 3 catalyst was investigated using a high pressure reaction system with a fixed bed reactor for the purpose to produce the chiral product without separating the catalyst from the reaction system. The reaction was also investigated in a batch reactor for comparison. About 60% e.e. and 90% e.e. were obtained with the fixed bed reactor and the batch reactor respectively, demonstrating the possibility for the heterogeneous asymmetric hydrogenation in the fixed bed reactor. Some adsorbed chiral modifier, cinchonidine, can be slowly removed from the surface of Pt/Al 2O 3 under the continuous flow reaction, as a result, the e.e. values drops with the reaction time in the fixed bed reactor. The enantio selectivity is higher in the fixed bed reactor, but lower in the batch reactor when ethanol was used as solvent than that when acetic acid as solvent. CO was used as molecular probe to characterize the adsorption of cinchonidine on the catalyst surface by IR spectroscopy. A red shift observed in IR spectra of coadsorbed CO with cinchonidine suggests that the cinchonidine adsorption is mainly through the π interaction with platinum surface and donating electron to the platinum surface.
关 键 词:Pt/γ-Al2O3催化剂 丙酮酸乙酯 不对称加氢
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:216.73.216.229