Constructing Internal Electric Field at Perovskite Heterojunction Interfaces and Electron Transfer-Enhanced Catalytic Soot Combustion

Under the operating conditions with low oxygen concentration in the air, the development of catalysts capable of efficiently activating molecular oxygen or in situ generating reactive oxygen species (ROS) is critical for achieving deep purification of soot in gasoline vehicle exhaust. Perovskite heterojunctions with tunable electronic structures and controllable built-in electric fields show great promise for applications in environmental catalysis. This study focuses on the efficient catalytic conversion of soot in automotive exhaust by constructing perovskite heterojunction catalysts. The built-in electric field of the heterojunctions drives interfacial charge separation and promotes the generation of reactive oxygen species (ROS), thereby significantly enhancing the soot oxidation activity. The experimental results demonstrate that the CeO2–LaFe0.6Co0.4O3 heterojunction exhibits the optimal catalytic performance under air atmosphere, achieving a soot conversion rate of 100% with its T10, T50, and T90 values being 428.97 °C, 494.73 and 538.95 °C, respectively. Mechanistic studies demonstrate that the built-in electric field across the heterojunction interface efficiently modulates electron transfer, which promotes the efficient regeneration and cycling of ROS as well as the multipath oxidation of soot, ultimately realizing low-temperature soot oxidation. This study provides an efficient and stable catalyst design strategy for soot abatement from automotive exhaust, and also offers theoretical and experimental foundations for the further application of perovskite-based heterojunctions in environmental catalysis.