Effect of synthesis methods on activity of V₂O₅/CeO₂/WO₃-TiO₂ catalyst for selective catalytic reduction of NO_x with NH₃

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• 作者：Meiqing SHEN ((沈美庆))^a ; ^b ; ^c ; Lili XU ((徐丽丽))^a ; Jianqiang WANG ((王建强))^a ; Chenxu LI ((李晨旭))^a ; Wulin WANG ((王务林))^a ; Jun WANG ((王 军))^a ; ^{wangjun@tju.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Yanping ZHAI ((翟燕萍))^d ; ^{yanpingzhai@chai.ac.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：V/WTi ; Ce-modified ; synthesis method ; Ce species ; NH3-SCR ; rare earths
• 刊名：Journal of Rare Earths
• 出版年：2016
• 出版时间：March 2016
• 年：2016
• 卷：34
• 期：3
• 页码：259-267
• 全文大小：1460 K

文摘

The effect of synthesis methods on the activity of V/Ce/WTi catalysts was investigated for the selective catalytic reduction (SCR) of NO_x 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 O_α 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-N₂O₂^2– 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.