Fe-Mn/Al₂O₃ catalysts for low temperature selective catalytic reduction of NO with NH₃

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• 作者：Xiaobo Wang^a ; ^b ; ^{winstonwell@126.com" class="auth_mail" title="E-mail the corresponding author} ; Shiguo Wu^a ; ^b ; Weixin Zou^a ; ^b ; Shuohan Yu^a ; ^b ; Keting Gui^c ; Lin Dong^a ; ^b ; ^{donglin@nju.edu.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Nitrogen monoxide ; Low-temperature selective catalytic reduction ; Fe-Mn catalyst ; X-ray photoelectron spectroscopy ; Sulfur dioxide ; Fourier transform infrared spectroscopy
• 刊名：Chinese Journal of Catalysis
• 出版年：2016
• 出版时间：August 2016
• 年：2016
• 卷：37
• 期：8
• 页码：1314-1323
• 全文大小：1257 K

文摘

A series of Fe-Mn/Al₂O₃ catalysts were prepared and studied for low temperature selective catalytic reduction (SCR) of NO with NH₃ in a fixed-bed reactor. The effects of Fe and Mn on NO conversion and the deactivation of the catalysts were studied. N₂ adsorption-desorption, X-ray diffraction, transmission electron microscopy, energy dispersive spectroscopy, H₂ temperature-programmed reduction, NH₃ temperature-programmed desorption, X-ray photoelectron spectroscopy (XPS), thermal gravimetric analysis and Fourier transform infrared spectroscopy were used to characterize the catalysts. The 8Fe-8Mn/Al₂O₃ catalyst gave 99% of NO conversion at 150 °C and more than 92.6% NO conversion was obtained in a wide low temperature range of 90–210 °C. XPS analysis demonstrated that the Fe³⁺ was the main iron valence state on the catalyst surface and the addition of Mn increased the accumulation of Fe on the surface. The higher specific surface area, enhanced dispersion of amorphous Fe and Mn, improved reduction properties and surface acidity, lower binding energy, higher Mn⁴⁺/Mn³⁺ ratio and more adsorbed oxygen species resulted in higher NO conversion for the 8Fe-8Mn/Al₂O₃ catalyst. In addition, the SCR activity of the 8Fe-8Mn/Al₂O₃ catalyst was only slightly decreased in the presence of H₂O and SO₂, which indicated that the catalyst had better tolerance to H₂O and SO₂. The reaction temperature was crucial for the SO₂ resistance of catalyst and the decrease of catalytic activity caused by SO₂ was mainly due to the sulfate salts formed on the catalyst.