Selective catalytic reduction of NOx by H_2 over Pd/TiO_2 catalyst
Selective catalytic reduction of NOx by H_2 over Pd/TiO_2 catalyst
复制标题
Pd/TiO_2催化剂上H_2选择性催化还原NOx
DOI：
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发表时间：
2019
影响因子：
16.5
通讯作者：
Zhiming Liu
中科院分区：
文献类型：
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作者：
Yiyang Zhang;Hui Zeng;Bin Jia;Zhihua Wang;Zhiming Liu
采用浸渍法、沉积沉淀法和聚乙二醇还原法制备了Pd/TiO_2催化剂，研究了H_2 （H_2- scr）选择性催化还原NO_x的性能。结果表明，制备方法对Pd/TiO_2催化剂的活性有显著影响，其中聚乙二醇还原法制备的Pd/TiO_2催化剂对NO_x的还原活性最高。催化剂的表征表明，聚乙二醇还原法制备的Pd/TiO_2催化剂中，现有的Pd组分为Pd0，是NO_x的H_2-SCR反应所需的组分。原位漂移研究表明，在这种催化剂上，形成了更多的螯合亚硝酸盐和单齿亚硝酸盐，这两种物质都是NO_x的H_2-SCR中的反应中间体。这些因素都是聚乙二醇还原法制备的Pd/TiO_2具有较高活性的原因。
Pd/TiO_2 catalysts prepared by three different methods (impregnation, deposition-precipitation, and polyethylene glycol reduction) were investigated in the selective catalytic reduction of NO_x by H_2 (H_2-SCR). It was found that the preparation method exerted a significant effect on the activity of the Pd/TiO_2 catalyst, and that the catalyst prepared by the polyethylene glycol reduction method exhibited the highest activity in the reduction of NO_x. Characterization of the catalyst showed that, in the Pd/TiO_2 catalyst prepared by the polyethylene glycol reduction method, the existing Pd species was Pd0, which is the desirable species for the H_2-SCR of NO_x. In situ DRIFTS studies demonstrated that over this catalyst, more chelating nitrite and monodentate nitrite species formed, both of which are reactive intermediates in the H_2-SCR of NO_x. All of these factors account for the high activity of Pd/TiO_2 prepared by the polyethylene glycol reduction method.