Tuning the A‐site Element in LaCo0.8Fe0.2O3 Perovskite‐based Catalyst for High Temperature N2O Decomposition in Nitric Acid Plant

Abstract The effect of La‐deficiency and Ce/Sr‐substitution in the benchmark LaCo 0.8 Fe 0.2 O 3 has been investigated for the decomposition of N 2 O between 500 and 900 °C. Real inlet gas composition and space velocity reveal that La‐deficiency and Ce/Sr‐substitution can improve the thermal stability of catalyst, while La 1‐ x Sr x Co 0.8 Fe 0.2 O 3 with x ≥0.1 was highlighted as a promising formula due to the strongest resistance to deactivation and suppressed undesired NO x decomposition at high space velocity. This phenomenon is mainly ascribed to the incorporation of Sr 2+ into the perovskite lattice during the reaction consequently stabilizing the Co 3+ species and creating the oxygen vacancies in La 1‐ x Sr x CoO 3‐δ . On the contrary, the loss of activity on Ce‐substituted LaCo 0.8 Fe 0.2 O 3 has been preferentially related to the cobalt exsolution to extra framework of perovskite making the catalytic cycle with Co 3+ unfavorable. All these bulk and surface changes are accompanied with opposite evolution of apparent activation energy and pre‐exponential factor which can be discussed based on a redox mechanism.