Abstract: Effective lattice oxygen (O_latt) activation at low temperatures has long been a challenge in catalytic oxidation reactions. Traditional thermal catalytic soot combustion, even with Pt/Pd catalysts, is inefficient at exhaust temperatures below 200  °C, particularly under conditions of frequent idling. Herein, we report an effective strategy utilizing non-thermal plasma (NTP) to activate O_latt in Ce_1-xCo_xO_2-δ catalysts, achieving dramatic enhancement of the soot combustion rate at low temperatures. At 200 °C and 4.3 W (discharge power, P_dis), NTP-Ce_0.8Co_0.2O_2-δ achieved 96.9% soot conversion (X_C), 99.0% CO₂ selectivity (S(CO₂)) and a maximum energy conversion efficiency (E_max) of 14.7 g kWh^-1. Compared with previously reported results, NTP-Ce_0.8Co_0.2O_2-δ exhibits the highest S(CO₂) and E_max values. Remarkably, even without heating, X_C, E_max, and S(CO₂) reached 92.1%, 6.1 g kWh^-1, and 97.5%, respectively, at 6.3 W (P_dis). The results of characterization and theoretical calculation demonstrated that Co dopes into the CeO₂ crystal lattice and forms an asymmetric Ce-O-Co structure, making oxygen “easy come, easy go”, thereby enabling the rapid combustion of soot over NTP-Ce_0.8Co_0.2O_2-δ. This study highlights the great potential of NTP for activating O_latt and provides valuable insights into the design of efficient NTP-adapted catalysts for oxidation reactions.

Key words: Reactive oxygen species, Lattice oxygen, Asymmetric Ce-O-Co structure, Non-thermal plasma, Soot combustion