Simultaneously elimination of NO and CO in the sintering flue gas is an urgent problem, in which the application of the bifunctional MnO catalyst has demonstrated its effectiveness in removing NO and CO simultaneously. Potassium salts are frequently found in the sintering flue gas and exert a detrimental influence on the catalytic performance of catalysts. Herein, the primary focus of this study is to investigate different K species (KSO, KCl, KNO) poisoning effect on bifunctional MnO. The findings suggested a deactivation order in the sequence of KNO > KCl > KSO. Fresh Mn-AC catalyst had finer grains, and poisoning elements were evenly distributed. XPS results revealed an obvious decrease in Mn and O species across all catalysts after K species poisoning, hindering redox cycle activation and oxygen species mobility, thus impacting catalytic activity. The DRIFTS results indicated the forbidden of E-R route over KNO-poisoned catalysts and low reactivity of adsorbed species after poisoning for NO removal. KNO severely suppressed surface reaction paths on Mn-AC catalyst and declined the catalytic efficiency, especially in CO activation. Finally, a possible reaction mechanism model for the simultaneous removal of NO and CO was proposed. This study could provide reference for the development of bifunctional catalyst with high resistance to potassium salts.

中文翻译：

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揭示钾盐对低温同时脱除NO和CO的MnOx催化剂的中毒效应

同时脱除烧结烟气中的NO和CO是一个紧迫的问题，其中双功能MnO催化剂的应用已证明其同时脱除NO和CO的有效性。烧结烟气中经常含有钾盐，对催化剂的催化性能产生不利影响。在此，本研究的主要重点是研究不同的 K 物种（KSO、KCl、KNO）对双功能 MnO 的中毒效应。研究结果表明，失活顺序为 KNO > KCl > KSO。新鲜的Mn-AC催化剂晶粒较细，中毒元素分布均匀。 XPS 结果显示，K 物质中毒后，所有催化剂中的 Mn 和 O 物质均明显减少，阻碍了氧化还原循环活化和氧物质迁移率，从而影响了催化活性。 DRIFTS 结果表明，KNO 中毒催化剂上的 ER 路线被禁止，中毒后吸附物质的 NO 去除反应活性较低。 KNO 严重抑制了 Mn-AC 催化剂的表面反应路径，降低了催化效率，特别是在 CO 活化中。最后，提出了同时去除NO和CO的可能反应机理模型。该研究可为开发高抗钾盐双功能催化剂提供参考。