Abstract A series of titanium modified FexMgyOz catalysts were prepared by coprecipitation method and impregnation-coprecipitation method with microwave assistant and their catalytic capability in selective catalytic reduction (SCR) was evaluated. Appropriate amount of either titanium or TiO2 could both improve the catalytic performance of FexMgyOz catalyst, especially above 350 °C. 7.5%Ti–FexMgyOz catalyst with wide temperature range of 225–400 °C could achieve the maximum NOx conversion of 100%, while FexMgyOz/TiO2(b) catalyst exhibited the best catalytic performance in the present of H2O and SO2. Characterization results exhibited that γ-Fe2O3 was the main active phase, TiO2 was mainly in the form of anatase TiO2 and both titanium and magnesium existed in amorphous phase. The crystalline grain could be refined with the addition of either titanium or TiO2, as well as the increase of BET surface area and pore volume. The acid sites, redox ability and the chemisorbed oxygen were the most important factors in SCR reaction. The introduction of titanium and TiO2 had the effect of increasing the strength of the acid sites, which could attribute to the improvement of catalytic performance over titanium modified FexMgyOz catalysts.

中文翻译：

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在钛改性 Fe x Mg y O z 催化剂上用 NH 3 选择性催化还原 NO x：性能和表征

摘要 采用共沉淀法和微波助剂浸渍-共沉淀法制备了一系列钛改性的FexMgyOz催化剂，评价了它们的选择性催化还原（SCR）催化能力。适量的钛或二氧化钛都可以提高 FexMgyOz 催化剂的催化性能，尤其是在 350°C 以上。7.5% Ti-FexMgyOz 催化剂在 225-400 °C 的宽温度范围内可以实现 100% 的最大 NOx 转化率，而 FexMgyOz/TiO2(b) 催化剂在 H2O 和 SO2 存在下表现出最好的催化性能。表征结果表明，γ-Fe2O3为主要活性相，TiO2主要以锐钛矿型TiO2形式存在，钛和镁均以非晶相存在。通过添加钛或二氧化钛，以及增加 BET 表面积和孔体积，可以细化晶粒。酸位、氧化还原能力和化学吸附氧是 SCR 反应中最重要的因素。钛和 TiO2 的引入具有增加酸位强度的作用，这可能归因于钛改性 FexMgyOz 催化剂的催化性能提高。