Manganese-based catalysts show high activities in selective catalytic reduction of nitrogen oxide (NO), but easily deactivated by sulfur dioxide. In this work, operation sequence and rare-earth-element doping were investigated to increase the anti-SO ability of Fe-doped manganese oxide (FM). On one hand, when the catalyst pre-adsorbed NH, SO only decreased the NO conversion from 100 % to 75 % at 200 °C. Otherwise, the conversion was decreased to 30 %. Diffuse Reflection Fourier Transform Infrared Spectroscopy proved that NH competed with SO and protected part of the Brønsted acidic sites. On the other hand, rare-earth-element doping increased the long-time anti-SO performance of FM from 150 min to 300 min (Sm-FM) and > 700 min (Ho-FM). Differential Scanning Calorimeter analysis indicated that Ho optimized ferromagnetism of FM, which was in favor of NH adsorption. The main result of this work will help to increase applicability of the manganese-based catalyst.

中文翻译：

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提高锰基催化剂抗SO2能力的两种简单方法

锰基催化剂在选择性催化还原氮氧化物（NO）方面表现出很高的活性，但很容易被二氧化硫失活。在这项工作中，研究了操作顺序和稀土元素掺杂，以提高铁掺杂锰氧化物（FM）的抗 SO 能力。一方面，当催化剂预吸附NH3、SO2时，200℃时NO转化率仅从100%降低至75%。否则，转化率会降低至 30%。漫反射傅里叶变换红外光谱证明NH与SO竞争并保护了部分Brønsted酸性位点。另一方面，稀土元素掺杂将FM的长期抗SO性能从150分钟提高到300分钟（Sm-FM）和> 700分钟（Ho-FM）。差示扫描量热仪分析表明Ho优化了FM的铁磁性，有利于NH的吸附。这项工作的主要结果将有助于提高锰基催化剂的适用性。