Effects of synthesis methods on catalytic activities of CoOx-TiO2 for low-temperature NH3-SCR of NO.
Effects of synthesis methods on catalytic activities of CoOx-TiO2 for low-temperature NH3-SCR of NO.
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DOI：
10.1016/j.jes.2016.09.014
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发表时间：
2017-04
影响因子：
6.9
通讯作者：
Li Zhu;Yiqing Zeng;Shule Zhang;Jinli Deng;Q. Zhong
中科院分区：
文献类型：
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作者：
Li Zhu;Yiqing Zeng;Shule Zhang;Jinli Deng;Q. Zhong
分别采用溶胶-凝胶法和浸渍法制备了一系列钴掺杂TiO 2（Co-TiO 2）和CoOx负载TiO 2（Co/TiO 2）催化剂，研究了其对NH3选择性催化还原NO（NH3-SCR）的影响，发现Co-TiO 2催化剂在低温范围内表现出更好的催化活性。通过XRD、TEM、拉曼和FT-IR等表征手段，证明Co物种通过置换Ti原子的方式掺杂到TiO 2晶格中。通过NH3-TPD、PL、XPS、EPR和DRIFTS等手段对Co-TiO 2催化剂进行表征和分析，发现Co-TiO 2催化剂比Co/TiO 2催化剂具有更好的NH3-SCR活性，这是由于Co-TiO 2催化剂上形成了更多的氧空位，从而促进了O2-的生成。超氧阴离子是通过与吸附的NO分子反应形成低温SCR反应中间体（NO3−）的关键。因此，这些因素是Co-TiO 2催化剂具有较高低温NH3-SCR活性的原因。
A series of cobalt doped TiO2(Co-TiO2) and CoOxloaded TiO2(Co/TiO2) catalysts prepared by sol–gel and impregnation methods respectively were investigated on selective catalytic reduction with NH3(NH3-SCR) of NO. It was found that Co-TiO2catalyst showed more preferable catalytic activity at low temperature range. From characterization results of XRD, TEM, Raman and FT-IR, Co species were proved to be doped into TiO2lattice by replaced Ti atoms. After being characterized and analyzed by NH3-TPD, PL, XPS, EPR and DRIFTS, it was found that the better NH3-SCR activities of Co-TiO2catalysts, compared with Co/TiO2catalyst, were ascribed to the formation of more oxygen vacancies which further promoted the production of more superoxide ions (O2−). The superoxide ions were crucial for the formation of low temperature SCR reaction intermediates (NO3−) by reacting with adsorbed NO molecule. Therefore, these aspects were responsible for the higher low temperature NH3-SCR activity of Co-TiO2catalysts.