Selective catalytic reduction of NOx with NH3 over short-range ordered W-O-Fe structures with high thermal stability
Selective catalytic reduction of NOx with NH3 over short-range ordered W-O-Fe structures with high thermal stability
复制标题
在具有高热稳定性的短程有序 W-O-Fe 结构上用 NH3 选择性催化还原 NOx
DOI：
10.1016/j.apcatb.2018.02.012
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
James A. Anderson
中科院分区：
文献类型：
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作者：
Ying Xin;Nana Zhang;Qian Li;Zhaoliang Zhang;Xiaoming Cao;Lirong Zheng;Yuewu Zeng;James A. Anderson
研究了贫晶W单键-Fe复合氧化物（WaFeOx）对NH3选择性催化还原NOx的反应。研究发现，W单键O单键Fe结构中存在的短程有序是其优异SCR活性的原因，其中Fe和W原子之间强的原子级相互作用促进了刘易斯和Brønsted酸性的形成.高角度环形暗场扫描透射电子显微镜（HAADF-STEM）显示，高温时效后，W单键O单键Fe结构以非晶覆盖层的形式存在于晶粒表面，厚度约为2 nm。在800 °C下处理5小时后，尽管表面积损失，但WaFeOx催化剂在300-450 °C范围内仍显示出几乎100%的NO转化率和100%的N2选择性。这种对高温老化影响的耐受性保证了SCR催化剂的高活性，SCR催化剂通常在高温偏移期间受到影响，如在柴油机排气的情况下，由于柴油机颗粒过滤器（DPF）再生。
The selective catalytic reduction (SCR) of NOxwith NH3was studied over poorly-crystalline Wsingle bondFe composite oxides (WaFeOx). The short-range order present within the Wsingle bondOsingle bondFe structure was found to be responsible for the excellent SCR activity, in which the strong atomic-level interaction between Fe and W atoms promoted the formation of both Lewis and Brønsted acidity. The Wsingle bondOsingle bondFe structure existed as amorphous overlayers, approximately 2 nm thick over the surface of crystalline particles after high-temperature aging as shown by high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM). After treatment at 800 °C for 5 h, the WaFeOxcatalysts still showed almost 100% NO conversion in the range 300–450 °C with 100% N2selectivity, despite the loss in surface area. This resistance to the impacts of high temperature ageing guarantees high activity of SCR catalysts which often suffer during high-temperature excursions as in the case of diesel exhaust due to diesel particulate filter (DPF) regeneration.