Effect of Transition-Metal Oxide M (M = Co, Fe, and Mn) Modification on the Performance and Structure of Porous CuZrCe Catalysts for Simultaneous Removal of NO and Toluene at Low–Medium Temperatures
Effect of Transition-Metal Oxide M (M = Co, Fe, and Mn) Modification on the Performance and Structure of Porous CuZrCe Catalysts for Simultaneous Removal of NO and Toluene at Low–Medium Temperatures
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过渡金属氧化物 M（M = Co、Fe 和 Mn）改性对中低温同时脱除 NO 和甲苯的多孔 CuZrCe 催化剂性能和结构的影响
DOI：
10.1021/acs.energyfuels.1c04407
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发表时间：
2022
期刊：
影响因子：
5.3
通讯作者：
Jiang Li
中科院分区：
文献类型：
--
作者：
Jun Tang;Lingkui Zhao;Su Jiang;Yan Huang;Junfeng Zhang;Jiang Li
为了满足非电厂烟气排放的特点，研究了不同过渡金属氧化物M（M=Co、Fe、Mn）修饰的多孔CuZrCe催化剂在中低温下同时脱除NO和甲苯的反应机理。 Brunauer-Emmett-Teller 分析、透射电子显微镜、X 射线衍射、氢气程序升温还原、NH3 程序升温解吸实验、X 射线光电子能谱和原位漫反射红外傅里叶变换光谱用于表征这些催化剂。结果表明，过渡金属氧化物的引入改善了织构和结构性能，提供了丰富的活性位点，并诱导更多活性氧的形成。此外，Mn++ Cu+↔ M(n–1)++ Cu2+ 和 Mn++ Ce3+↔ M(n–1)++ Ce4+ 的氧化还原平衡对于促进 NO 还原和甲苯氧化很重要。对于CuFeZrCe和CuMnZrCe，甲苯对NO转化表现出轻微的抑制作用，因为甲苯与NO竞争吸附在Cu2+位点上，而选择性催化还原（SCR）气氛由于NO消耗和新的布朗斯台德酸位点形成而促进甲苯吸附，从而促进甲苯氧化。对于CuCoZrCe，甲苯和SCR气氛表现出相互促进的作用，这主要归因于Co的添加为甲苯吸附提供了Co3+位点，抵消了NO和甲苯在Cu2+位点上的竞争吸附。
In order to satisfy the characteristics of non-power plant flue gas emissions, the reaction mechanism for the simultaneous removal of NO and toluene over different transition-metal oxide M (M = Co, Fe, and Mn)-modified porous CuZrCe catalysts was investigated at low–medium temperatures. Brunauer–Emmett–Teller analysis, transmission electron microscopy, X-ray diffraction, hydrogen temperature-programed reduction, temperature-programed desorption experiment with NH3, X-ray photoelectron spectroscopy, and in situ diffuse reflectance infrared Fourier transform spectroscopy were used to characterize these catalysts. The results show that the introduction of transition-metal oxides improved the texture and structural properties, supplied abundant active sites, and induced more reactive oxygen species formation. Also, the redox equilibrium of Mn++ Cu+↔ M(n–1)++ Cu2+and Mn++ Ce3+↔ M(n–1)++ Ce4+is important in promoting NO reduction and toluene oxidation. For CuFeZrCe and CuMnZrCe, toluene exhibited a slightly inhibitive effect on NO conversion because toluene competes with NO for adsorbing on the Cu2+sites, while the selective catalytic reduction (SCR) atmosphere facilitated toluene oxidation owing to NO consumption and new Brønsted acid site formation for toluene adsorption. For CuCoZrCe, toluene and SCR atmosphere showed mutual promoted effects, mainly attributed to Co addition that provided Co3+sites for toluene adsorption which offset the competitive adsorption on Cu2+sites between NO and toluene.