Direct N2O decomposition over La2NiO4-based perovskite-type oxides
Direct N2O decomposition over La2NiO4-based perovskite-type oxides
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La2NiO4 基钙钛矿型氧化物上 N2O 的直接分解
DOI：
10.1080/10962247.2014.941513
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发表时间：
2014
影响因子：
2.7
通讯作者：
M. Chang
中科院分区：
文献类型：
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作者：
K. Pan;S. Yu;S. Yan;M. Chang
研究了钙钛矿结构催化剂La2NiO4、LaSrNiO4和La0.7Ce0.3SrNiO4对N2O的直接分解作用。采用Pechini法制备了催化剂，并用x射线衍射（XRD）、BET、扫描电镜（SEM）和O2-TPD对催化剂进行了表征。实验结果表明，用Sr和Ce部分取代La能显著改善La2NiO4的性能。在400℃时，LaSrNiO4和La0.7Ce0.3SrNiO4的N2O分解效率分别为44%和36%。当温度提高到600℃时，在入口N2O浓度为1000 ppm、空速固定为8000 hr−1的条件下，LaSrNiO4和La0.7Ce0.3SrNiO4的N2O分解效率达到100%。此外，还探讨了氧、水蒸气、空速等参数对反应的影响。结果表明，当空间速度从8,000 hr−1增加到20,000 hr−1时，LaSrNiO4和La0.7Ce0.3SrNiO4对N2O的分解效率没有显著影响，而La0.7Ce0.3SrNiO4对O2和H2O的耐受性(g)更好。另一方面，以LaSrNiO4为催化剂，掺杂Ce可以显著提高N2产率。在气时空速为8000 hr−1，温度为600℃的条件下，在60 hr的耐久性试验中，La0.7Ce0.3SrNiO4的N2O分解效率和N2产率均保持较高，表明该材料对N2O的分解具有长期稳定性。结论：一氧化二氮（N2O）不仅具有很高的全球变暖潜势（GWP100 = 310），而且还可能破坏平流层中的臭氧。采用钙钛矿型催化剂La2NiO4、LaSrNiO4和La0.7Ce0.3SrNiO4直接分解N2O。结果表明，在La2NiO4中掺入Sr和Ce可以促进N2O的分解。在600℃时，LaSrNiO4和La0.7Ce0.3SrNiO4的N2O分解效率达到100%，表现出较高的活性和良好的直接分解N2O的潜力。还评价和讨论了O2和H2O(g)含量对催化活性的影响。
Direct decomposition of N2O by perovskite-structure catalysts including La2NiO4, LaSrNiO4, and La0.7Ce0.3SrNiO4 was investigated. The catalysts were prepared by the Pechini method and characterized by x-ray diffraction (XRD), BET, scanning electron microscopy (SEM), and O2-TPD. Experimental results indicate that the properties of La2NiO4 are significantly improved by partially substituting La with Sr and Ce. N2O decomposition efficiencies achieved with LaSrNiO4 and La0.7Ce0.3SrNiO4 are 44 and 36%, respectively, at 400ºC. As the temperature was increased to 600ºC, N2O decomposition efficiency achieved with LaSrNiO4 and La0.7Ce0.3SrNiO4 reached 100% at an inlet N2O concentration of 1,000 ppm, while the space velocity was fixed at 8,000 hr−1. In addition, effects of various parameters including oxygen, water vapor, and space velocity were also explored. The results indicate that N2O decomposition efficiencies achieved with LaSrNiO4 and La0.7Ce0.3SrNiO4 are not significantly affected as space velocity is increased from 8,000 to 20,000 hr−1, while La0.7Ce0.3SrNiO4 shows better tolerance for O2 and H2O(g). On the other hand, N2 yield with LaSrNiO4 as catalyst can be significantly improved by doping Ce. At a gas hour space velocity of 8,000 hr−1, and a temperature of 600ºC, high N2O decomposition efficiency and N2 yield were maintained throughout the durability test of 60 hr, indicating the long-term stability of La0.7Ce0.3SrNiO4 for N2O decomposition. Implications: Nitrous oxide (N2O) not only has a high global warming potential (GWP100 = 310), but also potentially destroys ozone in the stratosphere. Pervoskite-type catalysts including La2NiO4, LaSrNiO4, and La0.7Ce0.3SrNiO4 are applied for direct N2O decomposition. The results show that N2O decomposition can be enhanced as Sr and Ce are doped into La2NiO4. At 600ºC, N2O decomposition efficiencies achieved with LaSrNiO4 and La0.7Ce0.3SrNiO4 reach 100%, demonstrating high activity and good potential for direct N2O decomposition. Effects of O2 and H2O(g) contents on catalytic activities are also evaluated and discussed.