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采用溶胶-凝胶法通过在静态空气中700°C焙烧制备了不同Fe掺杂量的La0.7Sr0.3Co1-xFexO3(x=0,0.2,0.6,1.0)系列钙钛矿催化剂.考察了Fe掺杂量对催化剂的结构、氮氧化物储存、抗硫及再生性能的影响.研究结果表明:在La0.7Sr0.3CoO3钙钛矿B位用Fe部分取代Co,可有效提高SrCO3物相的分散,X射线衍射(XRD)结果显示样品中基本为钙钛矿物相.随着Fe掺杂量的增加,催化剂的NOx储存量(NSC)下降.对预硫化样品进行NOx储存测试,发现La0.7Sr0.3CoO3催化剂由于表面沉积了硫酸盐,同时钙钛矿结构也遭到了部分破坏,使得NOx储存量和NO氧化能力均大幅度下降,NOx储存量下降了64.2%,NO-to-NO2转化率从72.8%降至43.4%.掺杂Fe元素后,催化剂的抗硫性能都有不同程度的提高,特别是Fe掺杂量为60%的样品具有最佳的抗硫性能和可再生性能.与新鲜样品相比较,再生后样品的NOx储存量仅下降16.6%,而NO-to-NO2转化率为69.1%,几乎与新鲜样品相同.
La0.7Sr0.3Co1-xFexO3 (x = 0,0.2,0.6,1.0) series perovskite catalysts with different Fe doping amount were prepared by sol-gel method at 700 ° C in static air. The effects of Fe Doping amount on the structure of the catalyst, nitrogen oxide storage, anti-sulfur and regeneration performance.The results show that the partial substitution of Co with Fe in the B site of La0.7Sr0.3CoO3 perovskite can effectively improve the dispersion of SrCO3 phase , X-ray diffraction (XRD) results show that the sample is basically a perovskite phase.With the increase of Fe doping amount, the catalyst NOx storage (NSC) decreased.Pre-vulcanized samples for NOx storage test and found La0.7Sr0 .3 CoO3 catalyst deposited on the surface of the sulfate, while the perovskite structure has also been partially destroyed, making the NOx storage capacity and NO oxidation capacity were significantly reduced, NOx storage decreased by 64.2%, NO-to-NO2 conversion from 72.8% to 43.4% .After doped with Fe, the sulfur resistance of the catalyst increased to some extent, especially for the sample with 60% Fe doping content, which has the best sulfur resistance and renewable performance.Compared with the fresh Compared with the sample, the NOx storage of the sample after regeneration decreased by only 16.6%, while the NO-to-NO2 conversion was 69.1%, almost Same fresh sample.