NO reduction by CO over iron-based catalysts supported by activated semi-coke

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• 作者：Luyuan Wang ; Xingxing Cheng ; Zhiqiang Wang ; Xingyu Zhang and Chunyuan Ma
• 刊名：The Canadian Journal of Chemical Engineering
• 出版年：2017
• 出版时间：March 2017
• 年：2017
• 卷：95
• 期：3
• 页码：449-458
• 全文大小：3135K
• ISSN：1939-019X

文摘

Activated semi-coke was developed and loaded by iron species and other assistant metals (Co, La, and Ce) using a hydrothermal method to obtain the abatement of NO_x emissions from power plants and then used for NO removal by CO. These catalysts were systematically characterized by N₂ physisorption, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), and the activity of NO_x reduction. The results showed that the activated semi-coke that was loaded by Fe species could achieve an excellent NO_x conversion of 96.5 % at 350 °C with 0.2 g/g (20 wt%) of the precursor content (catalyst denoted as Fe20/ASC). This was ascribed to higher amounts of surface Fe³⁺ and chemisorbed oxygen. Furthermore, Co was the best promoter among Co, La, and Ce. This enhancement was attributed to the increase of the specific surface area and chemisorbed oxygen, as well as the formation of CoFe₂O₄. The synergistic effect between Fe and Co species was beneficial for the formation of oxygen vacancies, which could promote the adsorption and dissociation of NO. The in situ DRIFTS results indicated that the reaction for NO_x removal by CO over activated semi-coke supported catalysts mainly occurred between coordinated nitrates/nitryls and the adsorbed CO_x species.