Chemical deactivation of V2Os-WO3/Ti02 SCR catalyst by combined effect of potassium and chloride
V2O5-WO3/WiO2 catalyst was poisoned by impregnation with NHaC1, KOH and KC1 solution, respectively. The catalysts were characterized by X-ray diffraction （XRD）, inductively coupled plasma （ICP）, N2 physisorption, Raman, UV-vis, NH3 adsorption, temperature-programmed reduction of hydrogen （H2- TPR）,...
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| Published in: | 中国环境科学与工程前沿：英文版 no. 3; pp. 420 - 427 |
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| Main Author: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2013
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| Subjects: | |
| Online Access: | Get full text |
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| Summary: | V2O5-WO3/WiO2 catalyst was poisoned by impregnation with NHaC1, KOH and KC1 solution, respectively. The catalysts were characterized by X-ray diffraction （XRD）, inductively coupled plasma （ICP）, N2 physisorption, Raman, UV-vis, NH3 adsorption, temperature-programmed reduction of hydrogen （H2- TPR）, temperature-programmed oxidation of ammonia （NH3-TPO） and selective catalytic reduction of NOx with ammonia （NH3-SCR）. The deactivation effects of poison- ing agents follow the sequence of KC1 〉 KOH 〉〉 NH4CI. The addition of ammonia chloride enlarges the pore size of the titania support, and promotes the formation of highly dispersed V = O vanadyl which improves the oxidation of ammonia and the high-temperature SCR activity. K~ ions are suggested to interact with vanadium and tungsten species chemically, resulting in a poor redox property of catalyst. More importantly, potassium can reduce the Bronsted acidity of catalysts and decrease the stability of Bronsted acid sites significantly. The more severe deactivation of the KCl-treated catalyst can be mainly ascribed to the higher amount of potassium resided on catalyst. |
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| Bibliography: | 10-1013/X V2Os-WO3/TiO2, potassium chloride, poison-ing, reducibility, acid sites V2O5-WO3/WiO2 catalyst was poisoned by impregnation with NHaC1, KOH and KC1 solution, respectively. The catalysts were characterized by X-ray diffraction （XRD）, inductively coupled plasma （ICP）, N2 physisorption, Raman, UV-vis, NH3 adsorption, temperature-programmed reduction of hydrogen （H2- TPR）, temperature-programmed oxidation of ammonia （NH3-TPO） and selective catalytic reduction of NOx with ammonia （NH3-SCR）. The deactivation effects of poison- ing agents follow the sequence of KC1 〉 KOH 〉〉 NH4CI. The addition of ammonia chloride enlarges the pore size of the titania support, and promotes the formation of highly dispersed V = O vanadyl which improves the oxidation of ammonia and the high-temperature SCR activity. K~ ions are suggested to interact with vanadium and tungsten species chemically, resulting in a poor redox property of catalyst. More importantly, potassium can reduce the Bronsted acidity of catalysts and decrease the stability of Bronsted acid sites significantly. The more severe deactivation of the KCl-treated catalyst can be mainly ascribed to the higher amount of potassium resided on catalyst. |
| ISSN: | 2095-2201 2095-221X |