Selective catalytic reduction of nitric oxide by hydrogen over NiFe2-xPdxO4 catalysts at low temperature.
Selective catalytic reduction of nitric oxide by hydrogen over NiFe2-xPdxO4 catalysts at low temperature.
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DOI：
10.1016/j.cej.2015.08.089
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发表时间：
2016
影响因子：
15.1
通讯作者：
Chaochao Xu;Wei Sun;Limei Cao;Ji Yang
中科院分区：
文献类型：
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作者：
Chaochao Xu;Wei Sun;Limei Cao;Ji Yang
Selective catalytic reduction of NOxto nitrogen by hydrogen (H2-SCR) does not result in any secondary pollutants and can reduce NOxat the lowest possible temperatures. To achieve this goal, proper catalysts are critical. In this paper, NiFe2−xPdxO4catalysts were prepared using a sol–gel auto-ignition method for the selective catalytic reduction of NO with hydrogen (H2-SCR) in the presence of oxygen at 150–250 °C. The NiFe2−xPdxO4catalysts exhibited high SCR activity providing 100% NO conversion at 190 °C, and the activity improved as the palladium content increased. NiFe1.90Pd0.10O4exhibited a slightly lower activity in the 180–220 °C range. NiFe1.93Pd0.07O4and NiFe1.95Pd0.05O4exhibited larger acidity, higher level of reducibility and catalytic activity, which was validated through NH3-TPR, H2-TPR analysis and SCR activity tests. The XRD results indicated that the samples had a spinel cubic structure with good crystallization. The EDS results indicated that the Fe/Ni and Pd/Ni atomic ratio in the samples were consistent with the theoretical molecular formula (i.e., NiFe2−xPdxO4). The effects of GHSV, H2/NO ratios and O2feed concentration on the NO conversion over the NiFe1.95Pd0.05O4catalyst were also investigated. An increase in the O2concentration from 0% to 6% and a decrease in the H2/NO ratio from 10:1 to 5:1 produced only a slight decrease in the NO conversion. Studies on the effect of 3% and 5% H2O on the SCR activity concluded that the slight activity decrease, was due to reversible inhibition and weakly irreversible deactivation, and that the catalysts contained excellent water tolerance.
