Oxygen vacancy induced performance enhancement of toluene catalytic oxidation using LaFeO3 perovskite oxides

Surface oxygen vacancies have been demonstrated to be an important factor for volatile organic compounds (VOCs) catalytic oxidation. In this work, the oxygen vacancy over LaFeO3 perovskite oxides was tuned by the way of controlling A-site cation deficiency. The catalysts were synthesized through the Pechini method and investigated for the complete oxidation of toluene. Upon the strategy, the catalytic activity for the complete oxidation of toluene was enhanced obviously. The sample L0.90FO exhibited excellent catalytic performance, better than the stoichiometric sample LaFeO3 and commercial Fe2O3. Via analyzation of diversified characterization results, the introduction of A-site cation deficiency could affect the surface physicochemical properties to a certain extent, including enhanced oxygen vacancies, surface element valence state, and surface oxygen species content. Furthermore, through DFT calculation, the introduction of A-site cation deficiency could boost the formation of oxygen vacancies, consistent with the results of characterizations. Herein, the strategy of the introduction of A-site cation deficiency is one effective method to tune the surface oxygen vacancy which would benefit the catalytic performance of toluene catalytic oxidation.