氧化铈形貌对甲醇水蒸气重整制氢CuO/CeO2催化剂性能的影响

Morphology effect of ceria on the performance of CuO/CeO2 catalysts for hydrogen production by methanol steam reforming

摘要:

采用简单的改变焙烧气氛的方法改变水热法合成的CeO2纳米材料的形貌，得到的CeO2纳米材料再通过浸渍法制备CuO/CeO2催化剂，并将其应用于甲醇水蒸汽重整制氢反应。采用SEM、XRD、BET、H2-TPR、N2O滴定和XPS等对催化材料进行了表征，着重探讨了氧化铈形貌对催化剂结构、性质和性能的影响。结果表明，纳米棒状结构的CeO2负载CuO后得到的CuO/CeO2催化剂性能最佳，这主要是因为纳米棒状结构的CeO2与CuO的相互作用较强，表面存在较多的晶格缺陷和氧空穴，进而使得CuO/CeO2催化剂表相Cu含量增加，Cu物种的还原温度较低，催化活性较好。当反应温度为260 °C、水醇物质的量比为1.2、甲醇气体空速为800 h-1时，甲醇转化率可达100%，重整气中CO摩尔含量为0.16%。

Abstract:

CuO/CeO2 catalysts were prepared by impregnation method after the morphology of CeO2 nanomaterials first synthesized by hydrothermal method was changed by simply changing the roasting atmosphere, and the application of CuO/CeO2 catalysts to methanol steam reforming reaction was studied. The catalytic materials were characterized by SEM, XRD, BET, H2-TPR, N2O titration and XPS, and the effect of CeO2 morphology on the structure, property and performance of the catalysts was investigated. The results indicated that CuO/CeO2 catalysts, which were obtained from the CuO loaded by the nano-rods CeO2, demonstrated the best catalytic performance, because of the strong reaction between the nano-rods CeO2 and CuO, plenty of lattice defect and oxygen vacancy on the surface, therefore, the resulted increase of the surface Cu content of the CuO/CeO2 catalyst, the decrease of the reduction temperature of the Cu special, and hence the better catalytic activity. Over it, the methanol conversion was 100% and the CO concentration was 0.16% under 260 °C and with a water/methanol molar ratio of 1.2 and methanol gas hourly space velocity of 800 h-1.