Low-temperature Selective Catalytic Reduction of NOx over Ce-modified Fe2O3/AC Catalysts

doi:10.12034/j.issn.1009-606X.217360

Abstract

Abstract: A series of Fe2O3/AC and Ce?Fe2O3/AC catalysts with activated coke as support, iron and cerium as active ingredients were prepared by impregnation method. The influences of iron and cerium concentrations on the denitrification performance of the Fe2O3/AC catalyst at low temperature were investigated and these catalysts were characterized. The results showed that the Fe2O3/AC catalyst with 6wt% Fe had the best NOx conversion rate of 93.9% at 240℃. The NOx conversion rate using Ce-modified Fe2O3/AC catalyst was obviously improved. When the mass ratio of Ce to Fe was 0.5:6, the NOx conversion rate using Ce?Fe2O3/AC catalyst was higher 5%?20% than that using Fe/AC catalyst with 6wt% Fe at 120~200℃, and it showed a good sulfur resistance. The NOx conversion rate stabilized at 94.1% when the 100?10?6 (vol) SO2 was introduced at 240℃. The γ-Fe2O3 uniformly dispersed on the surface of catalyst after Ce modification, surface-adsorbed oxygen Oα ratio increased and reducibility was good, improving the NOx conversion rate.

Key words: γ-Fe2O3, Ce, Activated coke, Low-temperature, SCR

摘要： 以活性焦(AC)为载体、Fe和Ce为活性组分，采用等体积浸渍法制备了Fe2O3/AC和Ce?Fe2O3/AC催化剂，研究了Fe含量及Ce掺杂对Fe2O3/AC催化剂低温脱硝性能的影响，并对催化剂进行了表征. 结果表明，当Fe负载量为6wt%时，Fe2O3/AC催化剂的NOx转化率最高，240℃下达93.9%. 掺杂Ce后Ce?Fe2O3/AC催化剂的催化效率明显提高，当质量比Ce:Fe=0.5:6时，NOx转化率较高，120~200℃下NOx转化率比负载6wt% Fe的催化剂提高了5%?20%，且抗硫性能较好，240℃下通入100?10?6(vol) SO2，NOx转化率稳定在94.1%. 掺杂少量Ce可使γ-Fe2O3均匀分散在催化剂表面，且表面吸附氧Oα比例增大，催化剂的还原性增强，促进了选择性催化还原反应进行.

关键词: γ-Fe2O3, Ce, 活性焦, 低温, SCR

Shoulai YIN Baozhong ZHU Yunlan SUN Zhaohui ZI Cheng CHEN Guobo LI Tianyu XU. Low-temperature Selective Catalytic Reduction of NOx over Ce-modified Fe2O3/AC Catalysts[J]. Chin. J. Process Eng., 2018, 18(3): 509-516.

尹寿来朱宝忠孙运兰訾朝辉陈诚李国波徐天宇. Ce改性Fe₂O₃/AC催化剂低温SCR脱硝性能[J]. 过程工程学报, 2018, 18(3): 509-516.

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