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以铜锰硝酸、铜锰硫酸、铜锰醋酸和铜锰氯化盐为前驱体,采用共沉淀法制备了铜锰催化剂,利用XRD、TPR、STPR(表面氧化程序升温还原)、TPD和XPS等对样品进行了表征,并考察了其水煤气变换反应催化性能.结果表明,所制备的催化剂主晶相均为尖晶石结构的Cu1.5Mn1.5O4金属固溶体,经变换反应后均被还原分解为Cu和Mn O,其中以铜锰醋酸盐制备得到的样品出现了较为明显的Mn CO3特征衍射峰.铜锰醋酸盐制备的样品因单质铜和氧化锰协同效应良好,可显著增加对CO2的吸附能力,提高其表面铜的分散性,具有良好的热稳定性和低温变换反应活性.以铜锰硝酸盐制备的样品在400~450℃维持了较高的热稳定性及催化活性,但在300℃以下CO转化率明显下降,而以铜锰硫酸盐及铜锰氯化盐制备的样品在200~450℃测试温区内催化性能较差.
Copper-manganese catalysts were prepared by coprecipitation method using Cu, Mn, Cu, Mn, Cu, Mn and Cu-Mn chloride as precursors. The catalysts were characterized by XRD, TPR, STPR The samples were characterized and the catalytic performance of the water gas shift reaction was investigated.The results show that all the main crystalline phases of the catalyst are Cu1.5Mn1.5O4 solid solution with spinel structure and are all reductively decomposed to Cu and MnO, the obvious MnCO3 diffraction peaks appeared in the sample prepared from Cu-Mn acetate.The samples prepared from Cu-Mn acetate showed a synergistic effect due to the synergetic effect of elemental copper and manganese oxide, , Which has good thermal stability and low temperature shift reaction activity.The samples prepared from Cu, Mn and Mn nitrate maintained high thermal stability and catalytic activity at 400-450 ℃, At 300 ℃, the CO conversion decreased obviously. However, the samples prepared with Cu-Mn sulfate and Cu-Mn chloride showed poor catalytic performance in the temperature range of 200-450 ℃.