Selective catalytic reduction of NO (x) by hydrogen over modified Pd/TiO2-Al2O3 catalyst under lean-burn conditions
Selective catalytic reduction of NO (x) by hydrogen over modified Pd/TiO2-Al2O3 catalyst under lean-burn conditions
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贫燃条件下改性 Pd/TiO2-Al2O3 催化剂上氢气选择性催化还原 NO (x)
DOI：
10.1007/s11434-014-0473-5
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发表时间：
2014
影响因子：
--
通讯作者：
Yuan Lei
中科院分区：
文献类型：
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作者：
Duan Kaijiao;Liu Zhiming;Yuan Lei
采用等湿浸渍法制备了一系列镍、锡、钙改性的Pd/TiO2Al2O3型催化剂，考察了它们对H_2选择性催化还原NOx的催化性能。结果表明，在200℃以上，Pd-SnO/TiO2Al2O3型和PdNi型/TiO2Al2O3型催化剂的NOx转化率和N2选择性均有不同程度的提高，更重要的是PdSn2Al2O3型催化剂的N2选择性和高温活性远优于单一Pd/TiO2Al2O3型催化剂。最佳的锡载量为2wt.%。X-射线衍射仪结果表明，Pd和Sn之间的相互作用促进了Pd在TiO2-Al_2O_3上的分散。程序升温还原(H2-TPR)结果表明，锡的加入促进了Pd0的形成，改善了Pd/TiO2Al_2O_3的氧化还原性能。镍和锡的添加也促进了NOx的吸附和NO氧化为NO2，这在氢气选择性催化还原NOx中起着重要作用。
A series of Ni, Sn and Ca modified Pd/TiO2-Al2O3catalysts were prepared by the incipient wetness impregnation method and their catalytic performance for the selective catalytic reduction of NOxby H2was evaluated. The results showed that the NOxconversion and N2selectivity were improved over Pd-Sn/TiO2-Al2O3and Pd-Ni/TiO2-Al2O3catalysts above 200 °C. More importantly, the N2selectivity and high-temperature activity of Pd-Sn/TiO2-Al2O3catalyst was far superior to the single Pd/TiO2-Al2O3catalyst. The optimal Sn loading was 2 wt.%. X-ray diffraction (XRD) results showed that the interaction between Pd and Sn promotes the dispersion of Pd over TiO2-Al2O3. Temperature-programmed reduction (H2-TPR) results demonstrated that the addition of Sn contributes to the formation of Pd0and improving the redox property of Pd/TiO2-Al2O3. The additives of Ni and Sn also facilitated the absorption of NOxand the oxidation of NO to NO2, which play important roles in the selective catalytic reduction of NOxby hydrogen.