Fe‐Beta@CeO2 core‐shell catalyst with tunable shell thickness for selective catalytic reduction of NOx with NH3
Fe‐Beta@CeO2 core‐shell catalyst with tunable shell thickness for selective catalytic reduction of NOx with NH3
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DOI：
10.1002/aic.15743
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发表时间：
2017-10
期刊：
影响因子：
3.7
通讯作者：
Jixing Liu;Jian Liu;Zhen Zhao;Yuechang Wei;Weiyu Song
中科院分区：
文献类型：
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作者：
Jixing Liu;Jian Liu;Zhen Zhao;Yuechang Wei;Weiyu Song
设计并可控合成了一系列以小晶粒Beta负载FeOx纳米颗粒为核、可调CeO2薄膜厚度为壳的核壳结构脱硝催化剂。它们的催化性能通过 NH3 选择性催化还原 NOx (NH3-SCR) 进行了测试。研究发现CeO2壳厚度对催化剂的酸性和氧化还原性能起着重要的影响。 Fe-Beta@CeO2核壳催化剂在较宽的温度范围（225-565°C）内表现出优异的抗H2O和SO2性能以及高NOx转化率（90%以上）。动力学结果表明，CeO2壳的包覆显着提高了Fe-Beta@CeO2催化剂的孔扩散阻力。此外，原位 DRIFT 结果表明，CeO2 壳可以促进 NO2 和 cis-N2O2− 物种的形成。但太厚的CeO2壳层（~20 nm）会导致形成不活泼的硝酸盐物种，从而导致催化剂的高温活性下降。 © 2017 美国化学工程师学会 AIChE J, 63: 4430–4441, 2017
A series of core-shell structural deNOx catalysts using small-grain Beta supporting FeOx nanoparticles as the core and tunable CeO2 thin film thickness as sheaths were designed and controllably synthesized. Their catalytic performances were tested for selective catalytic reduction of NOx with NH3 (NH3-SCR). It was found that CeO2 shell thickness plays an important role in influencing the acidity and redox properties of the catalysts. Fe-Beta@CeO2 core-shell catalysts exhibit excellent resistance to H2O and SO2 and high NOx conversion (above 90%) in the wide temperature range (225–565°C). The kinetics result indicates that the coating of CeO2 shell significantly increases the pore diffusion resistance of Fe-Beta@CeO2 catalysts. Furthermore, in situ DRIFT results reveal that CeO2 shell can promote the formation of NO2 and cis- N2O2− species. But too thick CeO2 shell (∼20 nm) would result in the formation of inactive nitrate species, and thereby lead to a decrease of high-temperature activity of the catalysts. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4430–4441, 2017