Novel Fe-doped CePO4 catalyst for selective catalytic reduction of NO with NH3: The role of Fe3+ ions.
Novel Fe-doped CePO4 catalyst for selective catalytic reduction of NO with NH3: The role of Fe3+ ions.
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DOI：
10.1016/j.jhazmat.2019.121212
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发表时间：
2020-02
影响因子：
13.6
通讯作者：
Yiqing Zeng;Wang Song;Yanan Wang;Shule Zhang;Tianxiao Wang;Q. Zhong
中科院分区：
文献类型：
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作者：
Yiqing Zeng;Wang Song;Yanan Wang;Shule Zhang;Tianxiao Wang;Q. Zhong
首次通过简单的共沉淀法成功合成了新型Fe掺杂CePO4(FexCe1-x)催化剂，与FePO4和CePO4相比，表现出优异的NH3-SCR性能。为了研究Fe3+离子对CePO4催化剂NH3-SCR活性的促进作用，进行了各种表征。研究发现FexCe1-x催化剂的NH3容量受P位点控制并取决于其比表面积。有趣的是，FexCe1-x 中的 Fe 物种不是 NH3 吸附的路易斯酸位点，但它可以促进 NH3 的活化。更重要的是，Fe3+掺杂可以诱导Fe3++ Ce3+⇆ Fe2++ Ce4+的氧化还原平衡，从而显着改善CePO4催化剂的氧化还原性能。因此，FexCe1-x催化剂催化活性的提高可归因于更高的表面积、更好的氧化还原性能和易于活化的NH3的共同作用。其中，FexCe1-x催化剂优异的氧化还原性能是提高其高催化活性的主要原因。最后，通过原位DRIFT分析反应过程，提出CePO4和FexCe1-x上的NH3-SCR反应主要通过Eley-Rideal机理发生。我们预计这项工作可以促进新型NH3-SCR催化剂的发展。
Novel Fe-doped CePO4(FexCe1-x) catalyst was firstly successfully synthesizedviaa simple co-precipitation method and demonstrated excellent NH3-SCR performance in comparison with FePO4and CePO4. In order to study the promoting effects of Fe3+ion on the NH3-SCR activity of CePO4catalyst, various characterizations were conducted. It was found that NH3capacity of FexCe1-xcatalyst was controlled by P sites and depended on their specific surface area. Interestingly, Fe species in FexCe1-xwere not a Lewis acid site for NH3adsorption, but it could promote the activation of NH3. More importantly, Fe3+doping could induce the redox equilibrium of Fe3++ Ce3+⇆ Fe2++ Ce4+, which significantly improved redox properties of CePO4catalyst. Accordingly, improved catalytic activity of FexCe1-xcatalysts could be attributed to the collective effects of the higher surface area, better redox properties and easily activated NH3. Among them, superior redox property of FexCe1-xcatalysts was the main reason boosting their high catalytic activity. Finally, the reaction process analyzed by in situ DRIFT proposed that the NH3-SCR reaction over CePO4and FexCe1-xoccurred mainlyviaEley-Rideal mechanism. We anticipated this work could promote the development of novel NH3-SCR catalyst.