Combined Spectroscopic and Theoretical Approach to Sulfur-Poisoning on Cu-Supported Ti-Zr Mixed Oxide Catalyst in the Selective Catalytic Reduction of NOx
Combined Spectroscopic and Theoretical Approach to Sulfur-Poisoning on Cu-Supported Ti-Zr Mixed Oxide Catalyst in the Selective Catalytic Reduction of NOx
复制标题
铜负载 Ti-Zr 混合氧化物催化剂选择性催化还原氮氧化物中硫中毒的光谱与理论结合方法
DOI：
10.1021/cs5005739
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发表时间：
2014-08-01
期刊：
影响因子：
12.9
通讯作者：
Tade, Moses
中科院分区：
文献类型：
--
作者：
Liu, Jie;Li, Xinyong;Tade, Moses
采用原位傅里叶变换红外光谱（FTIR）结合密度泛函理论（DFT）研究了Cu/Ti 0. 7Zr 0. 3 O2-delta催化剂在C3 H6选择性催化还原（SCR）NOx反应中的SO2中毒行为，并探讨了SO2在不同反应温度下的不同作用.在低温（150-250摄氏度）的催化剂的原位FTIR结果表明，在表面上形成的硫酸盐抑制NO和C3 H6的活化以及硝酸盐和NO2的反应性。催化剂生成乙酸的能力减弱是低温下催化活性下降的重要原因。在高温下（高于275 ℃），SO2对C3 H6活化为乙酸盐的负面影响相当弱。更重要的是，通过反应-CN + SO2/SO 42- -> -NCO，-NCO物种的生成显着增强，这是由原位FTIR实验观察和DFT计算证实。促进-NCO物种的生成是高温下SCR活性升高的主要原因。
The SO2-poisoning on a Cu-supported Ti-Zr mixed oxide catalyst (Cu/Ti0.7Zr0.3O2-delta) in selective catalytic reduction (SCR) of NOx with C3H6 was investigated, and the different effects of SO2 at varying reaction temperatures were clarified by in situ Fourier transform infrared (FTIR) spectroscopy combined with density functional theory (DFT) calculations. In situ FTIR results of the catalyst at low temperatures (150-250 degrees C) implied that the formation of sulfates on the surface inhibited the activation of NO and C3H6 as well as the reactivity of nitrates and NO2. The weakened capacity of the catalyst toward acetate formation is an important reason for the decline of catalytic activity at low temperatures. At high temperatures (above 275 degrees C), the negative effect of SO2 on the C3H6 activation to acetate is quite weak. More importantly, the generation of -NCO species is enhanced significantly via the reaction -CN + SO2/SO42- -> -NCO, which is confirmed by both in situ FTIR experimental observations and DFT calculations. The promotion in the generation of -NCO species is the primary reason for the elevation of SCR activity at high temperatures.