Characteristics of Pt/WO3/CeO2/ZrO2 catalysts for catalytic reduction of NO by CO
Characteristics of Pt/WO3/CeO2/ZrO2 catalysts for catalytic reduction of NO by CO
复制标题
DOI：
10.1016/j.apcatb.2008.07.024
复制
发表时间：
2009-02
影响因子：
22.1
通讯作者：
Hai-ou Zhu;Jeong-Rang Kim;S. Ihm
中科院分区：
文献类型：
--
作者：
Hai-ou Zhu;Jeong-Rang Kim;S. Ihm
制备并表征了Pt/WO 3/CeO 2/ZrO 2、Pt/ZrO 2、Pt/CeO 2、Pt/CeZrO、Pt/WO 3/ZrO 2和Pt/WO 3/CeZrO等负载型Pt催化剂，考察了它们在有氧和无氧条件下催化CO还原NO的性能。TPR和CO-TPD结果表明，Pt/CeO 2和Pt/CeZrO易于被CO还原，而在Pt/WO 3/CeZrO中，引入WO 3后CO的还原反应受到抑制。NO-TPD结果表明，Pt/WO 3/CeZrO、Pt/ZrO 2、Pt/WO 3/ZrO 2催化剂上的NO在CO还原后仍不能还原为氧化态，而Pt/CeO 2和Pt/CeZrO 2催化剂上的NO在CO还原后仍能还原，对于NO+CO无氧反应，易还原催化剂（Pt/CeO 2和Pt/CeZrO 2）表现出较好的催化性能。而在氧过量时，Pt/WO 3/CeZrO和Pt/WO 3/ZrO 2催化剂表现出更高的NO转化率，尤其是在低温下。在Pt/WO 3/CeO 2/ZrO 2催化剂中，ZrO 2和WO 3的酸性对NO转化率的影响主要是在过量氧存在下。
Various supported Pt catalysts (Pt/WO3/CeO2/ZrO2; Pt/ZrO2, Pt/CeO2, Pt/CeZrO, Pt/WO3/ZrO2, and Pt/WO3/CeZrO) were prepared and characterized, and their characteristics of catalytic reductions of NO by CO with or without oxygen were investigated. TPR and CO-TPD showed that Pt/CeO2and Pt/CeZrO could be easily reduced by CO while the reduction by CO was inhibited with the introduction of WO3in the case of Pt/WO3/CeZrO. According to NO-TPD, NO reduction could not proceed over the catalysts (Pt/WO3/CeZrO, Pt/ZrO2, Pt/WO3/ZrO2) to remain in an oxidized state even after reduction by CO, but NO reduction was possible over Pt/CeO2and Pt/CeZrO catalysts when reduced by CO. For NO+CO reaction without oxygen, those easily reducible catalysts (Pt/CeO2and Pt/CeZrO) exhibited better catalytic performances. With excess oxygen, however, Pt/WO3/CeZrO and Pt/WO3/ZrO2catalysts exhibited higher NO conversions to N2and N2O especially at a low temperature. The acidity from ZrO2and WO3in Pt/WO3/CeO2/ZrO2catalysts should play an important role on their NO conversion only in the presence of excess oxygen.