Catalytic Performance of B-Site-Doped LaMnO3 Perovskite in Toluene Oxidation

The catalytic removal of toluene, a representative aromatic volatile organic compound (VOC), requires efficient and stable catalysts. This study systematically investigated the effect of B-site doping with transition metals (Fe, Cu, and Ni) on the catalytic performance of LaMnO3 perovskite for toluene oxidation. The LaMn0.5X0.5O3 catalysts were synthesized via a sol–gel method and evaluated. The LaMn0.5Ni0.5O3 catalysts exhibited the optimal catalytic performance, achieving toluene conversion temperatures of 243 °C at 50% conversion (T50) and 296 °C at 90% conversion (T90). Comprehensive characterization revealed that Ni doping effectively refined the catalyst’s microstructure (grain size decreased to 19.21 nm), increased the concentration of surface-active oxygen species (142.7%), elevated the Mn4+/Mn3+ ratio to 0.65, and enhanced lattice oxygen mobility. These modifications collectively contributed to its outstanding catalytic activity. The findings demonstrate that targeted B-site doping, particularly with Ni, is a promising strategy for engineering efficient perovskite catalysts for VOC abatement.