Optimization of Catalytic Soot Oxidation by 3DOM Perovskite‐Type La 0.5‐x K x Sr 0.5 CoO 3‐δ Catalysts: Structural Insights and K Substitution

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A series of 3DOM La 0.5‐x K x Sr 0.5 CoO 3‐δ catalysts were synthesized using colloidal crystal templating and citric acid complexation methods. The substitution of K ions for A‐site La ions was found to markedly enhance the catalysts’ intrinsic activity, with the La 0.4 K 0.1 Sr 0.5 CoO 3‐δ catalyst showing exceptional performance comparable to commercial precious metal catalysts. The La 0.4 K 0.1 Sr 0.5 CoO 3‐δ catalyst demonstrated the highest catalytic activity, with T 10 , T 50 , and T 90 values of 280 °C, 335 °C, and 387 °C, respectively. The enhancement in intrinsic activity is primarily attributed to the electron‐donating effect of K ions which maintains charge conservation and consequently increases the concentration of surface oxygen vacancies, leading to the formation of abundant active oxygen species. Additionally, the catalysts exhibited a highly ordered macroporous structure with interconnected pores, facilitating the diffusion of soot particles and enhancing contact efficiency with active sites. These findings not only advance the understanding of the structure‐performance relationship in perovskite catalysts but also pave the way for the development of cost‐effective catalysts for low‐temperature soot abatement.