Effect of Zirconium in La(Ba)ZrxCo1-xO3-δ Perovskite Catalysts for N2O Decomposition

Abstract

Zr-incorporated La(Ba)Zr x Co 1- x O 3- δ perovskites were prepared by a sol-gel method and used for the catalytic decomposition of the high concentrations of N 2 O present in propulsion applications. The introduction of Zr significantly enhanced N 2 O conversion, esp. with x = 0.05 and 0.2 for LaZr x Co 1- x O 3-δ and BaZr x Co 1- x O 3- δ , respectively. N 2 adsorption, X-ray diffraction, temperature-programmed reduction of H 2 , temperature-programmed desorption of O 2 , and oxygen pulse chemisorption techniques were used to characterize the structure and redox and oxygen adsorption property of the perovskites. The increasing of the surface area, modifying of the crystal structure, more facile reducibility of cobalt species, and higher oxygen desorption-adsorption activity due to the introduction of Zr were the reasons for the activity enhancement for N 2 O decomposition. 采用溶胶凝胶法制备了 Zr 掺杂的钴基钙钛矿 La(Ba)Zr x Co 1- x O 3- δ , 并将其用于航天推进剂领域的高浓度 N 2 O 催化分解反应. 发现 Zr 的引入明显提高了钙钛矿 La(Ba)Zr x Co 1- x O 3- δ 的催化活性, 尤其是当 Zr 掺杂量分别为 0.05 和 0.2 时, LaZr x Co 1- x O 3- δ 和 BaZr x Co 1- x O 3- δ 催化剂性能较为优异. 应用 N 2 物理吸附、X 射线衍射、H 2 程序升温还原、O 2 程序升温脱附和氧脉冲吸附技术表征了 Zr 掺杂对 La(Ba)Zr x Co 1- x O 3- δ 催化剂的物化性质的影响. 结果表明, Zr 掺杂增大了钴基钙钛矿的比表面积, 改善了晶格结构, 从而提高了钴物种的还原及氧吸附脱附能力, 因而催化剂上 N 2 O 分解活性增加. La(Ba)Zr x Co 1- x O 3- d catalysts were studied for the catalytic decomposition of N 2 O. The addition of Zr enhanced N 2 O conversion by increasing the surface area, reducibility of cobalt species, and oxygen desorption-adsorption activity.