Ce的浸渍顺序对Cu/Zn-Al水滑石衍生催化剂用于甲醇水蒸气重整制氢性能的影响

摘要

ZnAl-LDHs was prepared by in-situ synthesis method on γ-Al2O3and the Cu/Zn-Al,Ce/Cu/Zn-Al, Cu/Ce/Zn-Al and Cu-Ce/Zn-Al catalysts were then obtained by wet impregnation method for methanol steam reforming. The catalysts were characterized by XRD, XRF, SEM, N2sorption, XPS, H2-TPR and N2O titration;the effect of impregnation sequence of Ce on the performance of the Cu/Zn-Al catalysts in methanol steam reforming to produce hydrogen was investigated. The results showed that the impregnation sequence of Ce has a significant influence on the reducibility of resultant catalyst, which subsequently affects the catalytic performance. The Ce/Cu/Zn-Al catalyst exhibits the highest activity; over it, the methanol conversion reaches 100% under 250 ℃ and with a water/methanol molar ratio of 1.2 and gas hourly space velocity of 800 h-1, which is almost 40% higher than that achieved on the Cu/Zn-Al catalyst.%采用原位合成法在γ-Al2O3载体上合成了锌铝水滑石,再经浸渍法制备了Cu/Zn-Al、Ce/Cu/Zn-Al、Cu/Ce/Zn-Al和Cu-Ce/Zn-Al催化材料,使用XRD、XRF、SEM、氮吸附,XPS、H2-TPR和N2O滴定等手段对其进行了表征,探讨了Ce的浸渍顺序对Cu/Zn-Al水滑石衍生材料甲醇水蒸气重整制氢反应催化性能的影响.结果表明,Ce的浸渍顺序主要影响催化剂的还原性质,进而影响了其催化性能.其中,Ce/Cu/Zn-Al催化剂的催化性能最佳,在250℃、水醇物质的量比为1.2、甲醇气体空速为800 h-1的条件下,甲醇转化率达到100%;与Cu/Zn-Al催化剂相比,甲醇转化率提高了近40%.