A comparative study of Mn/CeO2, Mn/ZrO2 and Mn/Ce-ZrO2 for low temperature selective catalytic reduction of NO with NH3 in the presence of SO2 and H2O

Shen, Bo; Zhang, Xiaopeng; Ma, Hongqing; Yao, Yan; Liu, Ting

doi:10.1016/s1001-0742(12)60109-0

Cited by 124 publications

(35 citation statements)

References 53 publications

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“…Some of the published papers [17][18][19][20][27][28][29] have established that gold as well as manganese are components of active oxidation catalysts for VOC. Therefore, it was logical to expect that supported bi-component gold-manganese system could have the potential to become active oxidation catalysts.…”

Section: Introductionmentioning

confidence: 99%

Strong synergism between gold and manganese in an Au–Mn/triple-oxide-support (TOS) oxidation catalyst

Ali

Daous

Khamis

et al. 2015

Applied Catalysis A: General

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Section: Introductionmentioning

confidence: 99%

Strong synergism between gold and manganese in an Au–Mn/triple-oxide-support (TOS) oxidation catalyst

Ali

Daous

Khamis

et al. 2015

Applied Catalysis A: General

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“…As shown in Figure 8, the spectrum of all fresh catalysts exhibited three characteristic peaks at 3440 cm −1 , corresponding to the vibration of -OH units [39][40][41]; at 1645 cm −1 , which was ascribed to the stretching vibration of C=C on the surface of MWCNTs [42]; and a broad peak in the 1000-400 cm −1 range, which was attributed to the stretching vibration of metallic oxide groups (Me-O-Me) [43,44]. Compared to the fresh catalysts, a peak around 1102 cm −1 , assigned to the SO 4 2− species, appeared after reacting with SO 2 [6,45]. From the partial magnification of corresponding FTIR spectra, the peak became weaker after loading Ce or Y, indicating that the addition of Ce or Y may prevent the manganese active sites from being sulfated to some extent [46].…”

Section: Ftir Analysismentioning

confidence: 99%

Effect of Ce/Y Addition on Low-Temperature SCR Activity and SO2 and H2O Resistance of MnOx/ZrO2/MWCNTs Catalysts

et al. 2017

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Abstract:The effects of SO 2 and H 2 O on the low-temperature selective catalytic reduction (SCR) activity over MnO x /ZrO 2 /MWCNTs and MnO x /ZrO 2 /MWCNTs catalysts modified by Ce or Y was studied. MnCeZr and MnYZr catalysts reached nearly 100% and 93.9% NO x conversions at 200 • C and 240 • C, respectively. They displayed a better SO 2 tolerance, and the effect of H 2 O was negligible. The structural properties of the catalysts were characterized by XRD, H 2 -TPR, XPS, and FTIR before and after the reaction. The results showed that Ce could increase the mobility of the oxygen and improve the valence and the oxidizability of manganese, while the effect of Y was the opposite. This might be the main reason why the catalytic activity of MnCeZr was better than MnYZr in the presence or absence of SO 2 and H 2 O. Doping Ce or Y broadened the active temperature window. Ce or Y, which existed in the catalysts with a high dispersion or at the amorphous state, preferred to react with SO 2 to form sulfate species, and protected the manganese active sites from combing with SO 2 to some extent, which coincided with the theory of ionic polarization.

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“…The last step, above 470˝C, may have been the decomposition of metal sulfates during the heating process [11,37,38]. TGA results clearly indicated that sulfate species were formed on the catalyst surface.…”

Section: Influence Of So 2 and H 2 O On Scr Activity Of Catalystsmentioning

confidence: 99%

“…These results were consistent with TGA analysis, which likewise indicated that sulfates species were formed on the catalyst surface. Based on the results of TGA and FT-IR, the decrease of catalysts' activity had two likely causes: (1) the ammonium sulfate formed during the reaction was deposited on the catalyst surface and covered the active sites, blocking the active channels of the catalyst; and (2) the active components were sulfated by SO2, rendering them unable to generate effective intermediate species and thus inhibiting the SCR reaction [38,41].…”

Section: Catalysts Preparationmentioning

confidence: 99%

“…Ammonia solution (25%, AR, Sinopharm, Shanghai, China) was gradually added with continuous stirring until the pH reached 10, followed by stirring for another 1 h. The resulting precipitate was separated by filtration and washed thoroughly by centrifugation with deionized water, then the precipitate was collected and moved to an oven for drying at 120 °C for 12 h. The mixture was then ground and calcined in air at 500 °C for 4 h. Finally, the catalysts were compressed into tablet form and sieved to 40-60 mesh for testing and analysis. For Based on the results of TGA and FT-IR, the decrease of catalysts' activity had two likely causes: (1) the ammonium sulfate formed during the reaction was deposited on the catalyst surface and covered the active sites, blocking the active channels of the catalyst; and (2) the active components were sulfated by SO 2 , rendering them unable to generate effective intermediate species and thus inhibiting the SCR reaction [38,41].…”

Section: Catalysts Preparationmentioning

confidence: 99%

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Promotional Effect of Ce on Iron-Based Catalysts for Selective Catalytic Reduction of NO with NH3

Wang

Zhang

et al. 2016

Catalysts

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Abstract:A series of Fe-Ce-Ti catalysts were prepared via co-precipitation method to investigate the effect of doping Ce into Fe-Ti catalysts for selective catalytic reduction of NO with NH 3 . The NO conversion over Fe-Ce-Ti catalysts was considerably improved after Ce doping compared to that of Fe-Ti catalysts. The Fe(0.2)-Ce(0.4)-Ti catalysts exhibited superior catalytic activity to that of Fe(0.2)-Ti catalysts. The obtained catalysts were characterized by N 2 adsorption (BET), X-ray diffraction (XRD), temperature programmed reduction (H 2 -TPR), temperature programmed desorption (NH 3 -TPD), Fourier transform infrared (FT-IR) spectrophotometry, thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). The data showed that the introduction of Ce results in higher surface area and better dispersion of active components on the catalyst surface and enhances the amount of surface acid sites. The interactions between Fe and Ce species were found to improve the redox ability of the catalyst, which promotes catalytic performance at low temperature. The XPS results revealed that Fe 3+ /Fe 2+ and Ce 4+ /Ce 3+ coexisted on the catalyst surface and that Ti was in 4+ oxidation state on catalyst surface. Ce doping increased the atomic ratio of Fe/Ti and Ce/Ti and enhanced the surface adsorbed oxygen species. In addition, Fe(0.2)-Ce(0.4)-Ti catalyst also showed better tolerance to H 2 O and SO 2 and up to 92% NO conversion at 270˝C with 200 ppm SO 2 added over 25 h, which suggests that it is a promising industrial catalyst for mid-low temperature NH 3 -selective catalytic reduction (SCR) reaction.

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A comparative study of Mn/CeO2, Mn/ZrO2 and Mn/Ce-ZrO2 for low temperature selective catalytic reduction of NO with NH3 in the presence of SO2 and H2O

Cited by 124 publications

References 53 publications

Strong synergism between gold and manganese in an Au–Mn/triple-oxide-support (TOS) oxidation catalyst

Strong synergism between gold and manganese in an Au–Mn/triple-oxide-support (TOS) oxidation catalyst

Effect of Ce/Y Addition on Low-Temperature SCR Activity and SO2 and H2O Resistance of MnOx/ZrO2/MWCNTs Catalysts

Promotional Effect of Ce on Iron-Based Catalysts for Selective Catalytic Reduction of NO with NH3

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