B-site modulation of LaMO3 perovskites for catalyzing thermal decomposition of ammonium perchlorate

ABO 3 -type perovskite oxides have found extensive applications in various fields electrocatalysis and photocatalysis owing to their remarkable advantages such as facile synthesis, low cost, and high thermal stability. As catalytic materials, perovskites possess the ability to catalyze both oxidation and reduction reactions. The thermal decomposition process of AP involves a significant number of redox reactions. However, the utilization of perovskite catalysts for AP decomposition has received relatively limited research attention. In this study, LaMO 3 (M = Co, Fe, Al) perovskite catalysts were synthesized through the sol-gel method. The aim was to explore the disparities in band gap values and electrical conductivity caused by the substitution of different B-site elements. Subsequently, based on these properties, the catalytic mechanisms of AP thermal decomposition were analyzed. The results revealed that LaCoO 3 exhibits exceptional catalytic performance. The addition of LaCoO 3 significantly decreased the decomposition temperature of AP from 473.3 °C to 323.0 °C, lowered the activation energy from 465.5 kJ mol −1 to 182.9 kJ mol −1 , and increased the heat release from 88.8 J/g to 942.5 J/g. A series of characterizations, including XPS, EPR, DFT, EIS and UV–vis were performed on the three catalysts. The results demonstrate that perovskite catalytic materials with a narrower band gap and a higher concentration of oxygen vacancies exhibit superior electron transport efficiency and significantly enhanced thermal catalytic performance toward AP, thereby elucidating the underlying mechanism responsible for the differences in catalytic activity among the materials.