Direct Decomposition of NO over Cobalt-based Perovskite Catalyst La_1−xK_xCoO₃(x = 0.1–0.4) under Microwave Irradiation

Abstract

We presented the preparation and analysis of La_1−xK_xCoO₃ (x = 0.1–0.4) catalysts, supported on microwave-absorbing ceramic carriers, using the sol-gel method. We systematically investigated the effects of various reaction conditions under microwave irradiation (0–50 W). These conditions included reaction temperatures (300–600 °C), oxygen concentrations (0–6%), and varying K⁺ doping levels on the catalysts’ activity. The crystalline phase, microstructure, and the catalytic activity of the catalyst were analyzed by XRD, TEM, H₂-TPR, and O₂-TPD. The experimental results reveal that La_1−xK_xCoO₃ (x = 0.1–0.4) catalysts consistently form homogeneous perovskite nanoparticles across different doping levels. The NO decomposition efficiency on these catalysts initially increases and then decreases with variations in doping amount, temperature, and microwave power. Additionally, an increase in oxygen concentration positively influences NO conversion rates. The optimal performance is observed with La_0.7K_0.3CoO₃ catalyst under conditions of x = 0.3, 400 °C, 10 W microwave power, and 4% oxygen concentration, achieving a peak NO conversion rate of La_0.7K_0.3CoO₃ catalyst is 93.1%.

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Wuhan University of Technology and Springer-Verlag GmbH Germany, Part of Springer Nature