Fe修饰酸改性稀土精矿催化剂的NH_(3)-SCR性能研究

NH3-SCR performance of the Rare Earth concentrate catalysts activated by Fe modified acid

通过硫酸酸浸对稀土精矿进行改性处理使矿物表面的酸性位点增多和酸性增强,在此基础上,通过水热法引入不同量的Fe负载修饰矿物表面,XRD,SEM,BET,H_(2)-TPR,XPS等一系列表征探究稀土矿物催化剂性能与结构的关系.结果表明,负载0.015 mol Fe的样品,在400℃时NO_(x)转化率高达86%.随着Fe物种的引入,催化剂样品的比表面积明显增大且孔洞增多.XPS结果显示,催化剂活性组分Ce^(3+)明显增多,同时Fe以Fe^(2+)主导,有利于产生Fe—Ce协同作用.

The surface of the Rare Earth concentrates was modified by sulphuric acid leaching to increase the acidic sites and enhance the acidity of the mineral surface.On this basis,different amounts of Fe loading were introduced to modify the mineral surface by hydrothermal method,and XRD,SEM,BET,H_2-TPR,XPS and other series of characterizations were used to investigate the performance and structure of the modified rare earth mineral catalysts.When loading 0.015 mol Fe,the NO_x conversion rate is as high as 86%at 400℃.With the introduction of Fe species,the specific surface area and pores of catalyst samples increase significantly.The XPS results show that the active component Ce~(3+)increases significantly,and Fe is dominated by Fe~(2+),which is benificial to Fe-Ce synergism.