A number of nanostructured carbon materials were proposed as new effective promoters for preparing modified Cu/ZnO/Al 2O 3 catalyst system for efficient hydrogen production from methanol steam reforming. Compared to t...A number of nanostructured carbon materials were proposed as new effective promoters for preparing modified Cu/ZnO/Al 2O 3 catalyst system for efficient hydrogen production from methanol steam reforming. Compared to the catalysts modified by other type of carbon materials, the ACF-promoted catalyst prepared via carbonate-coprecipitation method exhibit the highest performance in the low-temperature steam reforming of methanol. It was suggested that the intrinsic high surface area nature of ACF material may favor the generation of modified catalysts with a high surface area and improved component dispersion, thus leading to improved performance for methanol steam reforming.展开更多
采用柠檬酸为络合剂,溶胶-凝胶法制备系列CeO_2-CuO/ZnO/Al_2O_3,在3.0 MPa压力和220~230℃反应条件下,甲苯二胺(TDA)和乙烯催化合成二乙基甲苯二胺(DETDA)为探针反应,考察其催化性能,其中CeO_2掺杂量为3%,催化活性最高。通过X射线衍射(...采用柠檬酸为络合剂,溶胶-凝胶法制备系列CeO_2-CuO/ZnO/Al_2O_3,在3.0 MPa压力和220~230℃反应条件下,甲苯二胺(TDA)和乙烯催化合成二乙基甲苯二胺(DETDA)为探针反应,考察其催化性能,其中CeO_2掺杂量为3%,催化活性最高。通过X射线衍射(XRD)、傅里叶红外光谱(FT-IR)、差热重量分析法(DTG-DTA)、核磁氢谱1 H NMR对CeO_2-CuO/ZnO/Al_2O_3、DETDA、TDA进行检测和表征,揭示了它们的微观结构和内在规律性。XRD检测发现CeO_2掺杂量增多,CeO_2-CuO/ZnO/Al_2O_3衍射峰强度增强,提高了晶化程度,金属原子存在协同效应,增多了活性中心。FT-IR揭示了DETDA内部化学键键型,拥有甲基、亚甲基的多取代芳胺。DTG-DTA检测出的质量变化与热效应两种信息,DETDA的DTG-DTA曲线在66.0、271.0℃存在二个吸热峰,分别为氨基脱离苯环、DETDA的分解产生。通过1 H NMR对DETDA、TDA检测,得到DETDA、TDA的氢原子的数目分别为18和10,分子中各个氢核对应所归属的吸收峰,分别和它们分子式中的氢原子数目吻合。CeO_2-CuO/ZnO/Al_2O_3催化合成DETDA,反应条件温和,工艺流程简单,容易实现高效率和连续化工业生产,因此具有广阔的发展前景。展开更多
A novel coprecipitation-reduction process has been proposed for preparing highly selective Cu/ZnO/Al 2O 3 catalysts for methanol synthesis from CO 2 hydrogenation. Compared to the catalysts prepared by the conventiona...A novel coprecipitation-reduction process has been proposed for preparing highly selective Cu/ZnO/Al 2O 3 catalysts for methanol synthesis from CO 2 hydrogenation. Compared to the catalysts prepared by the conventional method, the new catalysts prepared via the new method exhibit much higher BET surface area and pore size, much smaller crystallite size and higher catalytic activity and selectivity in CO 2 hydrogenation to methanol. It is also found that the molar ratio of Cu + to Cu 0 on the surface of the catalyst obtained by coprecipitation-reduction is much higher than that on the reduced catalyst obtained by the conventional method, which could be crucial for its high activity and selectivity for catalytic hydrogenation of CO 2 to methanol.展开更多
文摘A number of nanostructured carbon materials were proposed as new effective promoters for preparing modified Cu/ZnO/Al 2O 3 catalyst system for efficient hydrogen production from methanol steam reforming. Compared to the catalysts modified by other type of carbon materials, the ACF-promoted catalyst prepared via carbonate-coprecipitation method exhibit the highest performance in the low-temperature steam reforming of methanol. It was suggested that the intrinsic high surface area nature of ACF material may favor the generation of modified catalysts with a high surface area and improved component dispersion, thus leading to improved performance for methanol steam reforming.
文摘采用柠檬酸为络合剂,溶胶-凝胶法制备系列CeO_2-CuO/ZnO/Al_2O_3,在3.0 MPa压力和220~230℃反应条件下,甲苯二胺(TDA)和乙烯催化合成二乙基甲苯二胺(DETDA)为探针反应,考察其催化性能,其中CeO_2掺杂量为3%,催化活性最高。通过X射线衍射(XRD)、傅里叶红外光谱(FT-IR)、差热重量分析法(DTG-DTA)、核磁氢谱1 H NMR对CeO_2-CuO/ZnO/Al_2O_3、DETDA、TDA进行检测和表征,揭示了它们的微观结构和内在规律性。XRD检测发现CeO_2掺杂量增多,CeO_2-CuO/ZnO/Al_2O_3衍射峰强度增强,提高了晶化程度,金属原子存在协同效应,增多了活性中心。FT-IR揭示了DETDA内部化学键键型,拥有甲基、亚甲基的多取代芳胺。DTG-DTA检测出的质量变化与热效应两种信息,DETDA的DTG-DTA曲线在66.0、271.0℃存在二个吸热峰,分别为氨基脱离苯环、DETDA的分解产生。通过1 H NMR对DETDA、TDA检测,得到DETDA、TDA的氢原子的数目分别为18和10,分子中各个氢核对应所归属的吸收峰,分别和它们分子式中的氢原子数目吻合。CeO_2-CuO/ZnO/Al_2O_3催化合成DETDA,反应条件温和,工艺流程简单,容易实现高效率和连续化工业生产,因此具有广阔的发展前景。
基金The project supported by International Science and Technology Cooperation Key Program(No.2005DFA50450)Program of Educational Committee of Jiangxi Province(No.[2005]322[2006]309)
文摘A novel coprecipitation-reduction process has been proposed for preparing highly selective Cu/ZnO/Al 2O 3 catalysts for methanol synthesis from CO 2 hydrogenation. Compared to the catalysts prepared by the conventional method, the new catalysts prepared via the new method exhibit much higher BET surface area and pore size, much smaller crystallite size and higher catalytic activity and selectivity in CO 2 hydrogenation to methanol. It is also found that the molar ratio of Cu + to Cu 0 on the surface of the catalyst obtained by coprecipitation-reduction is much higher than that on the reduced catalyst obtained by the conventional method, which could be crucial for its high activity and selectivity for catalytic hydrogenation of CO 2 to methanol.
