Architecting multi-active center on 3DOM La_0.76Ce_0.19Ag_0.05Mn_0.9Co_0.1O_3-δ perovskite for soot oxidation

Precise construction of multiple active centers on perovskite oxides is recognized as a feasible and promising strategy to cooperatively promote the catalytic performances. Herein, 3DOM La_0.76Ce_0.19Ag_0.05Mn_0.9Co_0.1O_3-δ perovskite was designed and further treated within H₂/N₂ flow. High-temperature reduction did not destroy the original structure of perovskite, while the lattice Ag and Co were exsolved on perovskite surfaces to form Ag/Ag₂O and Co@Co₃O₄. Compared with the traditional impregnation method, this strategy provided the active nanoparticles with smaller size, higher dispersion, and stronger interaction with perovskite matrix. XPS and O₂-TPD indicated that the exsolved Ag and Co components could not only act as the O₂ activation sites to accelerate the generation of active oxygen species on surfaces, but also offered the electrons to the oxygen vacancy on the perovskite. In addition, the vacancy formed after A-site and B-site cations exsolution could also adsorb and activate O₂, ultimately boosting the catalytic combustion of soot. As a result, the developed perovskite exhibited a competitive catalytic activity with the T₅₀ of 364 ℃ under the condition of 500 ppm NO + 5 % O₂/N₂. This work offered a facile and effective pathway to assemble high-performance perovskite-type oxides for heterogeneous catalysis.