【摘要】 以机械混合法、浸渍法和共沉淀法分别制备了4%Ni-Al2O3催化剂,并用X射线衍射、程序升温还原、紫外-可见漫反射光谱和N2吸附等方法对催化剂的体相和表面结构进行了表征,系统考察了制备方法及焙烧温度对Ni-Al2O3催化剂催化丙烷选择性还原NO性能的影响.结果表明,Ni-Al2O3中存在NiO和NiAl2O4两种镍相,前者是丙烷氧化活性中心,后者是NO选择性催化还原的活性中心.共沉淀法制备的催化剂活性最好,550℃焙烧的Ni-Al2O3催化剂在反应温度为450和500℃时NO转化率接近100%.更多还原

【Abstract】 The selective catalytic reduction of nitric oxide（NO） by propane in excess oxygen was studied over 4%Ni-Al₂O₃ catalysts prepared by three different methods: mechanical mixture,impregnation and coprecipitation.The catalysts were characterized by X-ray diffraction,temperature-programmed reduction,diffuse reflectance UV-Vis spectroscopy and N₂ adsorption.The results show that the surface aluminate phase containing highly dispersed nickel metal cations in Al₂O₃ matrix is the active site for NO reduction,which is responsible for the high activity of the NAcp550 catalyst.The NiO phase is the active site for C₃H₈ oxidation by excess oxygen.The 4%Ni-Al₂O₃ catalysts prepared by coprecipitation show the best performance for NO reduction,and the catalyst calcined at 550 ℃ gives the highest activity with the NO conversion of 100% at 450 and 500 ℃.更多还原