Enhancement of nitric oxide decomposition efficiency achieved with lanthanum-based perovskite-type catalyst

Abstract

Direct decompositions of nitric oxide (NO) by La 0.7 Ce 0.3 SrNiO 4 , La 0.4 Ba 0.4 Ce 0.2 SrNiO 4 , and Pr 0.4 Ba 0.4 Ce 0.2 SrNiO 4 are experimentally investigated, and the catalysts are tested with different operating parameters to evaluate their activities. Experimental results indicate that the physical and chemical properties of La 0.7 Ce 0.3 SrNiO 4 are significantly improved by doping with Ba and partial substitution with Pr. NO decomposition efficiencies achieved with La 0.4 Ba 0.4 Ce 0.2 SrNiO 4 and Pr 0.4 Ba 0.4 Ce 0.2 SrNiO 4 are 32% and 68%, respectively, at 400°C with He as carrier gas. As the temperature is increased to 600°C, NO decomposition efficiencies achieved with La 0.4 Ba 0.4 Ce 0.2 SrNiO 4 and Pr 0.4 Ba 0.4 Ce 0.2 SrNiO 4 , respectively, reach 100% with the inlet NO concentration of 1000 ppm while the space velocity is fixed at 8000 hr −1 . Effects of O 2 , H 2 O (g) , and CO 2 contents and space velocity on NO decomposition are also explored. The results indicate that NO decomposition efficiencies achieved with La 0.4 Ba 0.4 Ce 0.2 SrNiO 4 and Pr 0.4 Ba 0.4 Ce 0.2 SrNiO 4 , respectively, are slightly reduced as space velocity is increased from 8000 to 20,000 hr −1 at 500°C. In addition, the activities of both catalysts (La 0.4 Ba 0.4 Ce 0.2 SrNiO 4 and Pr 0.4 Ba 0.4 Ce 0.2 SrNiO 4 ) for NO decomposition are slightly reduced in the presence of 5% O 2 , 5% CO 2 , or 5% H 2 O (g) . For durability test, with the space velocity of 8000 hr −1 and operating temperature of 600°C, high N 2 yield is maintained throughout the durability test of 60 hr, revealing the long-term stability of Pr 0.4 Ba 0.4 Ce 0.2 SrNiO 4 for NO decomposition. Overall, Pr 0.4 Ba 0.4 Ce 0.2 SrNiO 4 shows good catalytic activity for NO decomposition. Implications: Nitrous oxide (NO) not only causes adverse environmental effects such as acid rain, photochemical smog, and deterioration of visibility and water quality, but also harms human lungs and respiratory system. Pervoskite-type catalysts, including La 0.7 Ce 0.3 SrNiO 4 , La 0.4 Ba 0.4 Ce 0.2 SrNiO 4 , and Pr 0.4 Ba 0.4 Ce 0.2 SrNiO 4 , are applied for direct NO decomposition. The results show that NO decomposition can be enhanced as La 0.7 Ce 0.3 SrNiO 4 is substituted with Ba and/or Pr. At 600°C, NO decomposition efficiencies achieved with La 0.4 Ba 0.4 Ce 0.2 SrNiO 4 and Pr 0.4 Ba 0.4 Ce 0.2 SrNiO 4 reach 100%, demonstrating high activity and good potential for direct NO decomposition. Effects of O 2 , H 2 O (g) , and CO 2 contents on catalytic activities are also evaluated and discussed. PAPER HISTORY

Recent Progresses in Oxygen Reduction Reaction Electrocatalysts for Electrochemical Energy Applications

“…La-based perovskite oxides with La ions located in A-sites have been extensively investigated and applied in various applications [111][112][113][114][115][116], particularly in the catalysis of ORR [109,110,116]. For example, Sunarso et al [109] investigated the ORR activities of La-based perovskite oxides in alkaline media and reported that the increasing order of ORR activity for La-based perovskite oxides with different transition metal ions in B-sites was: LaCrO 3 < LaFeO 3 < LaNiO 3 < LaMnO 3 < LaCoO 3 .…”

Effect of Zinc on the Structure and Activity of the Cobalt Oxide Catalysts for NO Decomposition

“…Various catalytic materials have been studied, such as precious metals [2][3][4], transition metal ion-exchanged zeolites [5][6][7], perovskites [8,9], and rare earth oxides [10,11]. Among them, the cobalt mixed oxides with a spinel structure represent the promising group of catalysts due to their good redox properties [12][13][14][15][16][17].…”

Structure, Intrinsic properties and Vibrational Spectra of Pr(Mg1/2Sn1/2)O3 Ceramic Crystal

“…There are many researches on praseodymium based materials, for example, to study the GMR properties of praseodymium based perovskites Pr 0.7 (Sr, Ca) 0.3 Mn 1−x Al x O 3 and Pr 0.5 Sr 0.5 Mn 1−x Al x O 3 17 , to study the catalytic properties of Pr 0.4 Ba 0.4 Ce 0.2 SrNiO 4 18 , and to study the relationship between thermal expansion and oxygen ion transport of A 1−a A a ’BO 3 perovskite-type oxides 19 .…”