Effect of synthesis methods on activity of V2O5/CeO2/WO3-TiO2 catalyst for selective catalytic reduction of NOx with NH3
来源期刊:Journal of Rare Earths2016年第3期
论文作者:沈美庆 徐丽丽 王建强 李晨旭 王务林 王军
文章页码:259 - 267
摘 要:The effect of synthesis methods on the activity of V/Ce/WTi catalysts was investigated for the selective catalytic reduction(SCR) of NOx by NH3. V/Ce/WTi-DP(deposition precipitation) catalyst showed excellent NH3-SCR performance, especially the better medium-temperature activity and the less N2O formation than V/Ce/WTi-IMP(impregnation). These catalysts were characterized by X-ray diffraction(XRD), Brumauer-Emmett-Teller(BET), X-ray photoelectron spectroscopy(XPS), temperature-programmed reduction(H2-TPR), and in situ DRIFTS techniques. The XPS and H2-TPR results revealed that V/Ce/WTi-DP exhibited more surface Ce species, higher level of Oα and higher reducibility of Ce species. Reflected by in situ DRIFTS results, the deposition precipitation method(DP) contributed to a greater amount of weakly adsorbed NO2, monodentate nitrate and NH3 species with better reactive activity. Meanwhile, the cis-N2O22– species, an intermediate for N2O formation, was very limited. As a result, these advantages brought about the superior SCR activity and N2 selectivity for V/Ce/WTi-DP.
沈美庆1,2,3,徐丽丽1,王建强1,李晨旭1,王务林1,王军1
1. Key Laboratory for Green Chemical Technology of State Education Ministry, School of Chemical Engineering & Technology, Tianjin University2. Collaborative Innovation Center of Chemical Science and Engineering (Tianjin)3. State Key Laboratory of Engines, Tianjin University
摘 要:The effect of synthesis methods on the activity of V/Ce/WTi catalysts was investigated for the selective catalytic reduction(SCR) of NOx by NH3. V/Ce/WTi-DP(deposition precipitation) catalyst showed excellent NH3-SCR performance, especially the better medium-temperature activity and the less N2O formation than V/Ce/WTi-IMP(impregnation). These catalysts were characterized by X-ray diffraction(XRD), Brumauer-Emmett-Teller(BET), X-ray photoelectron spectroscopy(XPS), temperature-programmed reduction(H2-TPR), and in situ DRIFTS techniques. The XPS and H2-TPR results revealed that V/Ce/WTi-DP exhibited more surface Ce species, higher level of Oα and higher reducibility of Ce species. Reflected by in situ DRIFTS results, the deposition precipitation method(DP) contributed to a greater amount of weakly adsorbed NO2, monodentate nitrate and NH3 species with better reactive activity. Meanwhile, the cis-N2O22– species, an intermediate for N2O formation, was very limited. As a result, these advantages brought about the superior SCR activity and N2 selectivity for V/Ce/WTi-DP.
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