Cooperative effect induced by the mixing of Na-ZSM-5 and Pd/H3PW12O40/SiO2 in the selective catalytic reduction of NO with aromatic hydrocarbons
Cooperative effect induced by the mixing of Na-ZSM-5 and Pd/H3PW12O40/SiO2 in the selective catalytic reduction of NO with aromatic hydrocarbons
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DOI：
10.1016/j.apcatb.2007.04.008
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发表时间：
2007-09
影响因子：
22.1
通讯作者：
R. Yoshimoto;T. Ninomiya;K. Okumura;M. Niwa
中科院分区：
文献类型：
--
作者：
R. Yoshimoto;T. Ninomiya;K. Okumura;M. Niwa
将Pd负载到分散在SiO2表面的H3 PW 12 O 40（HPW）上，并将其应用于芳烃选择性还原NO反应中。以甲苯、二甲苯等支链芳烃为还原剂时，该催化剂表现出较高的NO还原活性。将Pd/HPW/SiO2与Na-ZSM-5进行物理混合，可显著提高其催化活性。甲苯程序升温脱附（TPD）和产物分析表明，Pd/HPW/SiO2与Na-ZSM-5混合后，催化剂的活性得到了提高。换句话说，芳族烃被部分氧化以产生氧化烃，例如，苯甲醛和邻苯二甲酸酐在Pd/Na-ZSM-5上的反应，在物理混合过程中，部分Pd从Pd/HPW/SiO2迁移到Na-ZSM-5上。随后，氧化烃与在Pd上用HPW捕获的NO反应以产生N2。
Pd was loaded on the dispersed H3PW12O40(HPW) over the SiO2surface, and the catalyst was applied to the selective reduction of NO with aromatic hydrocarbons. The catalyst exhibited high activity in the NO reduction when branched aromatic hydrocarbons, such as toluene and xylene, were used as reductants. The catalytic activity of Pd/HPW/SiO2was improved remarkably by physically mixing it with Na-ZSM-5. From the temperature programmed desorption (TPD) of toluene and the analysis of the products, it was inferred that the activity was enhanced when Pd/HPW/SiO2and Na-ZSM-5 were mixed. In other words, aromatic hydrocarbons were partially oxidized to yield oxygenated hydrocarbons, e.g., benzaldehyde and phthalic anhydride, over Pd/Na-ZSM-5; in this reaction, a part of Pd migrated from Pd/HPW/SiO2to Na-ZSM-5 during the course of the physical mixing procedure. Subsequently, the oxygenated hydrocarbons reacted with NO entrapped with HPW over Pd to yield N2.