Co/Ce0.5Zr0.5O2催化剂的制备及甲烷部分氧化制合成气

Preparation of Co/Ce_(0.5)Zr_(0.5)O_2 catalysts and their catalytic performance in methane partial oxidation to produce synthesis gas

利用共沉淀法制备了具有介孔结构的Ce0.5Zr0.5O2固溶体载体,然后浸渍不同质量分数(10%、20%、30%)的活性组分钴,制备了系列Co/Ce0.5Zr0.5O2催化剂。利用N2物理吸附(BET)、X射线粉末衍射(XRD)、H2-程序升温还原(H2-TPR)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、程序升温氧化(TPO)和热重(TG)等手段对制备和反应后的催化剂进行了表征,研究了它们对甲烷部分氧化制合成气反应的催化性能。研究结果表明,铈锆固溶体负载的钴比较容易被还原,该系列催化剂具有较高的活性和对H2及CO的选择性,且随Co含量的增加,催化剂的活性和对H2和CO的选择性得到提高的同时,也增强了催化剂的抗积炭性能。

Porous Ce0.5Zr0.5O2 solid solution support was first prepared by a co-precipitation method.Then,different concentrations of Co（10%,20%,and 30 %） were loaded over Ce0.5Zr0.5O2 by impregnation process.The fresh catalysts were characterized by some physicochemical characterizations such as N2 physical adsorption（BET）,X-ray diffraction（XRD）,temperature-programmed reduction of hydrogen（H2-TPR）,scanning electron microscopy（SEM）,and transmission electron microscopy（TEM）.The amount of deposited carbon over used catalysts was analyzed by temperature-programmed oxidation of oxygen（O2-TPO） and thermogravimetry（TG）.The catalytic performance of these Co/Ce0.5Zr0.5O2 catalysts was evaluated by methane partial oxidation to produce synthesis gas.The results show that cobalt oxide is easy to be reduced to metal cobalt over Ce0.5Zr0.5O2.This series of Co/Ce0.5Zr0.5O2 catalysts show high activity and selectivity to H2 and CO.It was found that loading high concentration of Co could benefit the increase in catalytic activity and ability to resist the coke.