Fe2O3-Cr2O3/TiO2系列催化剂的结构和脱硝性能

研究以纳米TiO2为载体,浸渍负载过渡金属氧化物,以CO为还原剂的脱硝催化剂的脱硝性能。实验中以计算量的Ni（NO3）2和Fe（NO3）3混合溶液浸渍纳米TiO2粉末,室温下搅拌30 min至混合均匀,放入旋转蒸发器中,70℃下至水分蒸干为止;所得粉末在550℃下、空气气氛中焙烧4 h即得所需催化剂。用以上方法分别制备2%Fe2O3-10%Cr2O3/TiO2、4%Fe2O3-8%Cr2O3/TiO2、6%Fe2O3-6%Cr2O3/TiO2、8%Fe2O3-4%Cr2O3/TiO2与10%Fe2O3-2%Cr2O3/TiO2等5种催化剂样品。实验结果表明,制备的催化剂具有较好的结构,分散较为均匀。对于CO＋NO反应,Fe2O3-Cr2O3/TiO2系列催化剂具有较好的催化活性,NO的转化率都达到了100%。其中,10%Fe2O3-2%Cr2O3/TiO2样品具有最好的低温活性,H2-TPR结果表明,这是由于10%Fe2O3-2%Cr2O3/TiO2催化剂更易于被CO预还原。

Structure and denitrification behaviors of Fe2O3-Cr2O3/TiO2 catalysts

This work aimed to investigate the performance of a denitration catalyst,which uses nanometer TiO2 as support,transition metal oxides as active component and CO as reducer.Nanometer TiO2 powder was dipped by the mixture of Fe（NO3）3 and Cr（NO3）3,kept stirring for 30 min until well mixed at room temperature,and then it was evaporated to dryness in rotary evaporator at 70℃.The samples obtained with this process were calcined at 550℃ for 4 h in air atmosphere to prepare the catalysts.In this experiment,five catalysts produced by this method,2%Fe2O3-10%Cr2O3/TiO2,4%Fe2O3-8%Cr2O3/TiO2,6%Fe2O3-6%Cr2O3/TiO2,8%Fe2O3-4%Cr2O3/TiO2 and 10%Fe2O3-2%Cr2O3/TiO2,were investigated.Experimental results indicate that the Fe2O3-Cr2O3/TiO2 catalysts series,with excellent structure and dispersity,have great catalytic activity to the reaction NO＋ CO and the conversion of NO reaches 100%.Of all the prepared catalysts,10%Fe2O3-2%Cr2O3/TiO2 catalyst shows the best activity at lower temperature,due to fact that it could more easily be pre-reduced by CO,which is proved by the H2-TPR results.