Amorphous Boron Dispersed in LaCoO₃ with Large Oxygen Vacancies for Efficient Catalytic Propane Oxidation

Abstract

Unsatisfactory oxygen mobility is a considerable barrier to the development of perovskites for low-temperature volatile organic compounds (VOCs) oxidation. This work introduced small amounts of dispersed non-metal boron into the LaCoO₃ crystal through an easy sol-gel method to create more oxygen defects, which are conducive to the catalytic performance of propane (C₃ H₈ ) oxidation. It reveals that moderate addition of boron successfully induces a high distortion of the LaCoO₃ crystal, decreases the perovskite particle size, and produces a large proportion of bulk Co²⁺ species corresponding to abundant oxygen vacancies. Additionally, surface Co³⁺ species, as the acid sites, which are active for cleaving the C-H bonds of C₃ H₈ molecules, are enriched. As a result, the LCB-7 (molar ratio of Co/B=0.93:0.07) displays the best C₃ H₈ oxidation activity. Simultaneously, the above catalyst exhibits superior thermal stability against CO₂ and H₂ O, lasting 200 h. This work provides a new strategy for modifying the catalytic VOCs oxidation performance of perovskites by the regulation of amorphous boron dispersion.