采用共沉淀-微波热解法制备一系列不同Mg掺杂比的Fe1-xMgxOz（x=0,0.1,0.2,0.3）催化剂,研究Mg掺杂对γ-Fe2O3催化剂SCR脱硝活性的影响,并借助XRD,N2吸附-脱附、SEM和EDS等手段对催化剂进行表征。Mg的最佳掺杂比为0.2,且Fe0.8Mg0.2Oz催化剂在325℃时脱硝效率可达99.1%,同时活性温度窗口为250350℃。Fe0.8Mg0.2Oz催化剂主要活性组分为γ-Fe2O3,其中Mg以无定型状态存在,能够与晶格中的Fe相互作用形成良好的固溶体,其较大的比表面积（44.00 m2/g）、比孔容（0.19 cm3/g）为反应气体在催化剂表面吸附与活化提供了丰富的表面活性位;合理的孔结构分布、良好的孔间连通性则利于传质的快速进行。Fe(0.8Mg0.2Oz催化剂最佳O2体积分数为3%,推荐NH3/NO为1;催化剂表面氧化能力的提高及反应物的快速吸附、活化有利于NH3-SCR反应的进行。

A series of magnetic iron-magnesium mixed oxide catalysts (Fe1-xMgx Oz ,where x = 0,0. 1,0. 2,0. 3) were synthesized via a novel co-precipitation method with microwave thermal treatment and their activities were tested on a quartz fixed-bed reactor. Physical properties of the catalysts were characterized by X-ray diffraction ( XRD),N2 -ad- sorption-desorption,Scanning Electron Microscope (SEM) and Energy Dispersive Spectrometer (EDS). Fe0. 8 Mg0. 2 Oz with a wide temperature window of 250 ℃ to 350 ℃ was validated as the proper SCR catalyst,and the maximum NOx conversion of 99. 1% was achieved at 325 ℃ . Activity was strongly influenced by the γ-Fe2 O3 crystalline phase,mag- nesium existed in an amorphous phase and interacted with iron oxide intensively to form solid solution. Optimum pore diameter distribution,appropriate surface area (44. 00 m2 / g),pore volume (0. 19 cm3 / g) and abundant lattice oxy- gen could be guaranteed in Fe0. 8 Mg0. 2 Oz catalyst,which was good for the diffusion process and enhanced the activity. The optimum O2 concentration of Fe0. 8 Mg0. 2 Oz catalyst was 3% ,and recommended NH3 / NO was 1. The improvement of oxidation ability on the surface of the catalyst and the rapid adsorption and activation of reactants were both in favor of NH3 -SCR reaction.