In this paper, selective catalytic reduction (SCR) of N₂O by CO was investigated over Fe-beta zeolites catalysts. The catalysts were prepared by wet ion-exchange (IE), impregnation (IM) and solid state ion-exchange (SSIE) methods. These catalysts were characterized by XRD, UV–vis DR spectroscopy, H₂-TPR, TPD and in-situ DRIFTS. At 350 °C, more than 90% N₂O conversion could be obtained over the Fe-beta-IE catalyst. The activity for N₂O removal of Fe-beta-IE was higher than Fe-beta-IM and Fe-beta-SSIE catalysts. The UV–vis spectra showed that 84.2% of isolated Fe^(III) ion appeared on Fe-beta-IE catalyst. It indicated that the isolated Fe^(III) ions might be considered as the active sites for N₂O reduction. Besides, in the presence of H₂O, the activities in CO-SCR for N₂O removal over Fe-beta catalysts were inhibited, which might be due to the hydroxylation deactivation of iron species and excess accumulation of carbonates.

Graphic Abstract

中文翻译：

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Fe-β沸石对CO选择性催化还原N 2 O的影响：铁物种分布的影响

本文研究了在Fe-β沸石催化剂上用CO选择性催化N ₂ O的还原反应（SCR）。通过湿离子交换（IE），浸渍（IM）和固态离子交换（SSIE）方法制备催化剂。这些催化剂的特征在于XRD，UV-vis DR光谱，H ₂ -TPR，TPD和原位DRIFTS。在350℃下，在Fe-β-IE催化剂上可获得超过90％的N ₂ O转化率。Fe-β-IE的N ₂ O去除活性高于Fe-β-IM和Fe-β-SSIE催化剂。紫外可见光谱表明，有84.2％的分离出的Fe ^（III）离子出现在Fe-beta-IE催化剂上。表明分离出的Fe ^（III）离子可被视为还原N ₂ O的活性位点。此外，在H ₂ O存在的情况下，CO-SCR中通过Fe-β催化剂去除N ₂ O的活性受到抑制，这可能是由于铁物种的羟基化失活和碳酸盐的过量积累。

图形摘要