The role of surface properties of silicotungstic acid doped CeO2 for selective catalytic reduction of NOx by NH3: Effect of precipitant
The role of surface properties of silicotungstic acid doped CeO2 for selective catalytic reduction of NOx by NH3: Effect of precipitant
复制标题
硅钨酸掺杂CeO2表面性质对NH3选择性催化还原NOx的作用：沉淀剂的影响
DOI：
10.1016/j.molcata.2015.12.009
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发表时间：
2016-03
期刊：
影响因子：
--
通讯作者：
Zhenzhen Huang
中科院分区：
文献类型：
--
作者：
Jinhui Zhang;Yancai Wang;Yankang Duan;Zhenzhen Huang
本文研究了CeO 2沉淀剂对CeO 2负载硅钨酸催化剂还原NOx活性的影响。结果表明，采用氨水沉淀法制备的硅钨酸掺杂CeO 2具有最佳的SCR性能，在225-450 °C时，NOx转化率接近100%。NH3·H2O（Cat-A）制备的硅钨酸掺杂CeO 2被（111）和（220）晶面包围，（NH 4）2CO 3（Cat-B）制备的催化剂主要暴露于（220）和（200）晶面，而NH3·H2O和（NH 4）2CO 3混合物（Cat-C）制备的催化剂仅暴露于（200）晶面。Cat-B和Cat-C催化剂的比表面积和总孔容均比Cat-A催化剂的大幅度降低。此外，B酸中心仅出现在Cat-A催化剂上，且刘易斯酸强度明显强于Cat-B和Cat-C催化剂。重要的是，Cat-A具有较高的Ce 3+浓度和表面化学吸附氧Oα。结果表明，CeO 2的（111）和（200）表面的结构几何形状和表面酸性不同，这与沉淀剂的种类有关。
The present work elucidated the precipitants effect of pure CeO2on the activity of silicotungstic acid supported on CeO2catalysts toward NOxreduction. The results implied that the silicotungstic acid doped CeO2prepared by the NH3·H2O precipitant showed the best SCR performance and nearly 100% NOxconversion was obtained at 225–450 °C. Silicotungstic acid doped CeO2prepared by NH3·H2O (Cat-A) was enclosed by (1 1 1) and (2 2 0) planes; the catalyst with (NH4)2CO3(Cat-B) predominantly exposed (2 2 0) and (2 0 0) surfaces, and the catalyst with the mixture of NH3·H2O and (NH4)2CO3(Cat-C) merely exhibited the (2 0 0) planes. Moreover, the aggregated WO3was observed over the Cat-B and Cat-C, the BET surface areas and total pore volume of the two samples significantly decreased compared with Cat-A. Besides, the Brönsted (B) acid sites only appeared on the Cat-A catalyst and the intensity of Lewis acid was visibly stronger than that of Cat-B and Cat-C. Importantly, the Cat-A possessed its higher concentration of Ce3+and surface chemisorbed oxygen Oα. As a result, the structure geometry and surface acidity were different on the (1 1 1) and (2 0 0) surfaces of CeO2, which were dependence on the different precipitants.
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影响因子：
3.7
作者：
Zhichun Si;D. Weng;Xiaodong Wu;Jiang Yang;Bin Wang
通讯作者：
Zhichun Si;D. Weng;Xiaodong Wu;Jiang Yang;Bin Wang
影响因子：
7.3
作者：
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影响因子：
6.1
作者：
Xiaopeng Zhang;B. Shen;Kai Wang;Jianhong Chen
通讯作者：
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影响因子：
3.7
作者：
B. M. Reddy;P. Bharali;P. Saikia;Ataullah Khan;S. Loridant;M. Muhler;W. Grünert
通讯作者：
B. M. Reddy;P. Bharali;P. Saikia;Ataullah Khan;S. Loridant;M. Muhler;W. Grünert