NiO/LaMnO_3催化剂用于乙醇水蒸气重整反应

NiO/LaMnO_3 Catalysts for Steam Reforming of Ethanol

采用柠檬酸络合-浸渍法制备了NiO/LaMnO3钙钛矿型复合氧化物催化剂并将其应用于乙醇水蒸汽重整制氢反应,考察了NiO含量、焙烧温度对催化剂性能的影响,采用XRD、TPR和热分析等手段对催化剂进行了表征.结果表明,该催化剂具有高活性、高选择性和良好的稳定性.催化剂中的NiO含量和焙烧温度对催化性能有显著影响.在原料气体积组成为20%(体积分数,!)C2H5OH和水以及80%(!)N2,其中水醇摩尔比为3∶1,空速为80000mL·h-1·gc-a1t,反应温度为400℃时,15%(质量分数,w)的NiO/LaMnO3上,乙醇转化率接近100%.关联催化剂活性和TPR及XRD实验结果,发现催化剂的高活性源于由催化剂前驱体中进入钙钛矿型复合氧化物晶格中的镍离子被还原所得的金属镍.

Perovskite type oxides supported nickel catalysts NiO/LaMnO3 were prepared by citric-complexing and impregnation method and used for H2 production by steam reforming of ethanol. The influence of nickel content and the calcination temperature on the catalytic performance was investigated. The catalysts were characterized by temperature programmed reduction （TPR）, X-ray diffraction （XRD）, and thermal analysis techniques. The catalysts showed very good catalytic performance. The NiO/LaMnO3 catalyst with NiO content of 15% （mass fraction, w） in catalysts and calcined at 700 ℃ exhibited the highest activity. Nearly 100% conversion of ethanol was observed over this catalyst at reaction temperature of 400 ℃, in reaction mixtures of 20% （volume fraction, φ） C2H5OH＋H2O and 80%（φ） N2 with a molar ratio of water and ethanol of 3∶1 and at a gas hourly space velocity （QHSV） 80000 mL·h-1·g-1cat. By combining catalytic performance and characterization results, it was proposed that the high activity was ascribed to the metal nickel reduced from nickel ions in the lattice of perovskite type oxides.