Low-Temperature Selective Catalytic Reduction of NOx with NH3 over Novel Mn–Zr Mixed Oxide Catalysts

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• 作者：Jianliang Zuo ; Zhihang Chen ; Furong Wang ; Yinghao Yu ; Lefu Wang ; Xuehui Li
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2014
• 出版时间：February 19, 2014
• 年：2014
• 卷：53
• 期：7
• 页码：2647-2655
• 全文大小：481K
• ISSN：1520-5045

文摘

Novel Mn鈥揨r mixed oxide catalysts have been prepared by the citric acid method for the low-temperature selective catalytic reduction (SCR) of NO_x with ammonia in the presence of excess oxygen. They have been characterized by a series of techniques, specifically N₂ adsorption鈥揹esorption, X-ray diffraction (XRD), temperature programmed reduction (TPR), temperature programmed desorption (TPD), and X-ray photoelectron spectroscopy (XPS). It was found that an Mn(0.5)鈥揨rO_x-450 (Mn/(Mn + Zr) mole ratio of 0.5) catalyst showed the highest activity, giving 100% NO_x conversion at 100 掳C with a space velocity of 30鈥?00 h^鈥?. XRD results suggested that an Mn鈥揨r solid solution was formed in the Mn(0.5)鈥揨rO_x-450 catalyst, with highly dispersed MnO_x. TPR data indicated a strong interaction between the zirconium oxide and manganese oxide, which improved the reduction ability of the MnO_x. The TPD results indicated that an appropriate NH₃ adsorption ability was beneficial for the low-temperature SCR. The catalyst showed a certain level of sulfur tolerance and water resistance. The effect of H₂O could be quickly eliminated after its removal, whereas deactivation by SO₂ proved to be irreversible.