Direct decomposition of N
2O by perovskite-structure catalysts including La
2NiO
4, LaSrNiO
4, and La
0.7Ce
0.3SrNiO
4 was investigated. The catalysts were prepared by the Pechini method and characterized by x-ray diffraction (XRD), BET, scanning electron microscopy (SEM), and O
2-TPD. Experimental results indicate that the properties of La
2NiO
4 are significantly improved by partially substituting La with Sr and Ce. N
2O decomposition efficiencies achieved with LaSrNiO
4 and La
0.7Ce
0.3SrNiO
4 are 44 and 36%, respectively, at 400ºC. As the temperature was increased to 600ºC, N
2O decomposition efficiency achieved with LaSrNiO
4 and La
0.7Ce
0.3SrNiO
4 reached 100% at an inlet N
2O 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 N
2O decomposition efficiencies achieved with LaSrNiO
4 and La
0.7Ce
0.3SrNiO
4 are not significantly affected as space velocity is increased from 8,000 to 20,000 hr
?1, while La
0.7Ce
0.3SrNiO
4 shows better tolerance for O
2 and H
2O
(g). On the other hand, N
2 yield with LaSrNiO
4 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 N
2O decomposition efficiency and N
2 yield were maintained throughout the durability test of 60 hr, indicating the long-term stability of La
0.7Ce
0.3SrNiO
4 for N
2O decomposition.
Implications:Nitrous oxide (N
2O) not only has a high global warming potential (GWP
100 = 310), but also potentially destroys ozone in the stratosphere. Pervoskite-type catalysts including La
2NiO
4, LaSrNiO
4, and La
0.7Ce
0.3SrNiO
4 are applied for direct N
2O decomposition. The results show that N
2O decomposition can be enhanced as Sr and Ce are doped into La
2NiO
4. At 600ºC, N
2O decomposition efficiencies achieved with LaSrNiO
4 and La
0.7Ce
0.3SrNiO
4 reach 100%, demonstrating high activity and good potential for direct N
2O decomposition. Effects of O
2 and H
2O
(g) contents on catalytic activities are also evaluated and discussed.
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