Abstract In this paper, CePO4 and CeCO3F were prepared by hydrothermal synthesis based on the ratio of bastnaesite to monazite in the process mineralogy of Baiyun Ebo rare earth concentrate. A comparison of the two treatments, ball milling and ball milling sulphation, revealed that the denitrification efficiency of the catalysts treated with ball milling sulphation increased by 20 percentage points, compared to those treated without sulphation, with denitrification efficiencies of up to 80%. The surface properties, redox properties and catalytic mechanism of the samples before and after the sulphation treatment were analyzed, by using XRD, NH3-TPD, H2-TPR, XPS and in situ IR characterization. The results showed that the CeF3 diffraction peaks in the XRD patterns disappeared in the sulphated samples, NH3-TPD showed that the adsorption capacity of NH3 on the surface of the samples was enhanced, and the introduction of sulphuric acid provided a large number of acidic sites on the catalyst surface, among which the Lewis acidic sites might be more favorable for the promotion of SCR reaction. The acidification of sulphuric acid greatly increases the redox capacity of the catalyst, and the interconversion between Cen+ was enhanced. XPS showed a significant increase in the amount of adsorbed oxygen on the surface of the sample. The presence of -NO2, an important intermediate in the L-H mechanism, was also detected by IR analysis. reactant species during the L-H mechanism reaction were monodentate nitrate, bridged nitrate and NH4 + species produced by NH3 adsorption on the Brønsted acidic site of the catalyst surface.

中文翻译：

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白云鄂博稀土精矿中铈基物质NH3-SCR的研究

摘要 本文根据白云鄂博稀土精矿工艺矿物学中氟碳铈矿与独居石的配比，采用水热合成法制备了CePO4和CeCO3F。比较球磨和球磨硫酸盐化两种处理方法后发现，与未经硫酸盐化处理的催化剂相比，经球磨硫酸盐化处理的催化剂的脱硝效率提高了 20 个百分点，脱氮效率高达 80%。通过XRD、NH3-TPD、H2-TPR、XPS和原位IR表征分析了硫酸化处理前后样品的表面性质、氧化还原性质和催化机理。结果表明，硫酸盐样品的XRD图谱中的CeF3衍射峰消失，NH3-TPD表明NH3在样品表面的吸附能力增强，硫酸的引入在催化剂表面提供了大量酸性位点，其中路易斯酸性位点可能更有利于促进SCR反应。硫酸酸化大大提高了催化剂的氧化还原能力，增强了Cen+之间的相互转化。XPS 显示样品表面吸附氧的量显着增加。LH 机制中的重要中间体 -NO2 的存在也通过 IR 分析检测到。LH 机理反应过程中的反应物种类是单齿硝酸盐、桥联硝酸盐和 NH3 吸附在催化剂表面的 Brønsted 酸性位点上产生的 NH4 + 物质。