低温水煤气变换催化剂Cu/ZrO_2的制备、表征与性能

以水热法制得的纯单斜相ZrO2为载体,采用沉积沉淀法制备了一系列具有良好水煤气变换反应活性的Cu/ZrO2催化剂.并通过X射线粉末衍射、N2物理吸附、H2程序升温还原、X射线荧光元素分析、高分辨透射电镜和扫描电镜等手段考察了制备参数对Cu/ZrO2催化剂结构的影响,探讨了其结构与性能的关系.结果表明,CuO负载量、沉淀温度、沉淀剂种类和焙烧温度均在一定程度上影响了催化剂活性组分的晶粒大小、分散状态、织构性质及载体与活性组分间的相互作用,从而影响催化剂活性.催化剂制备的适宜条件为:CuO负载量25%,沉淀温度65oC,KOH为沉淀剂,在H2气氛300oC焙烧2h.

Cu/ZrO2 Catalyst for Low-Temperature Water-Gas Shift Reaction:Preparation, Characterization and Performance

A series of Cu/ZrO2 catalyst samples with excellent catalytic performance for low-temperature water-gas shift(WGS) reaction were prepared by a two-step method.First,pure monoclinic ZrO2 support was prepared by hydrothermal synthesis,and then a certain amount of CuO was deposited on the support by deposition-precipitation.The catalyst samples were characterized by X-ray diffraction,N2-physisorption,H2 temperature-programmed reduction,X-ray fluorescence elemental analysis,high resolution transmission electron microscopy,and scanning electron microscopy,aiming to know the effect of preparation parameters on the catalytic performance of these samples.The relationship between their catalytic performance and structures was discussed.The crystalline size and dispersity of the Cu particles,texture of Cu/ZrO2 catalyst samples as well as the interaction between ZrO2 and Cu are greatly influenced by the preparation conditions,such as the CuO amount,precipitation temperature,precipitant and calcination temperature.And the optimal preparation parameters are ZrO2 loaded with 25% CuO,precipitation at 65 oC with KOH as precipitant,and calcination at 300 oC for 2 h purging with H2.