Abstract:

SCR de-NO _x catalyst Cu-HPMo/TiO₂ was prepared by maceration method using anatase TiO₂ as support and Cu modified phosphorous molybdenum heteropoly acid (HPMo) as active component. The effects of Cu doping ratio, catalyst calcination temperature and the loading of active component on the denitration efficiency were studied, and the structure and properties of the catalyst were analyzed by means of XRD, BET and SEM, etc. The activity test results showed that the denitration efficiency of the catalyst was the highest when the mole ratio of Cu and Mo(Cu∶Mo) was 3∶1, calcination temperature was 350℃ and the loading of active component was 10%. The denitration efficiency was 92% at 200℃ and it increased to 99% at 250℃.The BET analysis showed that the addition of Cu increased the dispersion of the active components on the surface of the catalysts leading to an enlarged surface area. Proper amount of Cu doping and calcining temperature are beneficial for enhancing the interaction between Cu and Mo, which could facilitate the dispersion of the active components, the decrease of the grain volume, the connection between grains and the denitration efficiency.

Key words: selective catalytic reduction, catalyst, fixed-bed, phosphomolybdic acid, Cu doping

摘要：

选用锐钛矿型TiO₂作为载体，以磷钼杂多酸（HPMo）掺杂Cu作为活性组分，采用浸渍法制备了Cu-HPMo/TiO₂负载型杂多酸SCR脱硝催化剂。研究了Cu掺杂比例、催化剂煅烧温度和活性组分负载量等因素对催化剂脱硝效率的影响，并通过XRD、BET和SEM等表征方法对催化剂结构特性进行了表征分析。活性测试结果表明，当活性组分配比为Cu∶Mo=3∶1，煅烧温度为350℃，活性组分负载量为10%时，催化剂的脱硝效率最佳，催化剂在200℃时NO _x 去除率即达到92%，在250℃时有着最高99%的NO _x 去除率。XRD和BET等表征结果显示，Cu的加入增加了活性组分在催化剂表面的分散性，使比表面积增大；适量的Cu掺杂和适宜的煅烧温度有利于增强Cu与Mo的相互作用，使得活性组分分散性良好，晶粒体积减小，晶粒之间连接紧密及催化脱硝活性提高。

关键词: 选择性催化还原, 催化剂, 固定床, 磷钼酸, Cu掺杂