Catalytic selective reduction of NO with propylene over Cu-Al2O3 catalysts: influence of catalyst preparation method
Catalytic selective reduction of NO with propylene over Cu-Al2O3 catalysts: influence of catalyst preparation method
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DOI：
10.1016/s0926-3373(99)00084-3
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发表时间：
1999-12
影响因子：
22.1
通讯作者：
Laiyuan Chen;T. Horiuchi;T. Osaki;Toshiaki Mori
中科院分区：
文献类型：
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作者：
Laiyuan Chen;T. Horiuchi;T. Osaki;Toshiaki Mori
研究了四种不同方法制备的Cu-Al_2 O_3催化剂，即浸渍法、共沉淀法、混合水溶液蒸发法和干凝胶法，并对催化剂的CO还原性能进行了比较。结果表明，催化剂的制备方法以及Cu含量对催化剂活性有显著影响。对于前三种制备方法制备的催化剂，随着Cu含量从5wt%增加到15wt%，最大NO还原转化率略有下降，但最大NO还原温度也有所降低。对于干凝胶Cu-Al_2 O_3，随着Cu含量从5%增加到10%，NO还原转化率显著降低。在无水蒸气存在下，浸渍法制备的Cu-Al_2 O_3催化剂具有最高的NO还原活性。氧化铝载体的纯度是影响浸渍法制备的Cu-Al_2 O_3催化剂活性的关键因素。在水蒸气存在下，前三种方法制备的Cu-Al_2 O_3催化剂的NO转化率均显著降低，尤其是浸渍法制备的Cu-Al_2 O_3催化剂。相比之下，水蒸气的存在下，显示只有一个很小的影响，干凝胶5wt%的Cu-Al 2 O 3和它表现出最高的NO还原活性在20%的水蒸气的存在下。干凝胶5 wt % Cu-Al_2 O_3催化剂也被发现比其他方法制备的Cu-Al_2 O_3催化剂更少受到5wt%硫酸盐沉积的影响。
NO reduction to N2by C3H6was investigated and compared over Cu-Al2O3catalysts prepared by four different methods, namely, the conventional impregnation, co-precipitation, evaporation of a mixed aqueous solution, and xerogel methods. It was found that the catalyst preparation method as well as the Cu content exerts a significant influence on catalyst activity. For the catalysts prepared by the first three preparation methods, with the increase of Cu content from 5 to 15wt%, the maximum NO reduction conversion decreased slightly, but the temperature for the maximum NO reduction also decreased. For the xerogel Cu-Al2O3, there was a significant decrease in NO reduction conversion with the increase of Cu content from 5 to 10wt%. In the absence of water vapour, the Cu-Al2O3catalyst prepared by the impregnation method exhibited the highest activity toward NO reduction. The purity of alumina support was found to be a crucial factor to the activity of the Cu-Al2O3catalyst prepared by impregnation. In the presence of water vapour, a substantial decrease in NO conversion was observed for the Cu-Al2O3catalysts prepared by the first three methods, especially for the impregnated Cu-Al2O3catalyst. In contrast, the presence of water vapour showed only a minor influence on the xerogel 5wt% Cu-Al2O3and it showed the highest activity for NO reduction in the presence of 20% water vapour. The xerogel 5wt% Cu-Al2O3catalyst was also found to be less affected by a 5wt% sulfate deposition than the Cu-Al2O3catalysts prepared by other methods.