Interface engineering constructs Co-O_V-Ce/La interfacial sites with dual "capture-clear" functionality to enhance...

The rational design of interfacial sites is crucial for developing high-performance, water-resistant carbon monoxide (CO) oxidation catalysts. Herein, Co-O_V-Ce/La interfacial sites were constructed in cobalt oxide (Co₃O₄) by co-doping with Ce/La, yielding the La₂O₃-CeO₂@Co₃O₄ catalyst with outstanding water resistance. At 150 °C under a 20 vol% water (H₂O) flow, the catalyst achieved 92% CO conversion, outperforming most previously reported non-precious metal catalysts. The introduction of Ce and La induced lattice distortion, generated oxygen vacancies (O_V), activated oxygen species, and enhanced oxidation activity. Especially, O_V content in La₂O₃-CeO₂@Co₃O₄ was increased 1.89-fold compared to pure Co₃O₄, which promoted the formation of Co-O_V-Ce/La interfacial sites. Density functional theory (DFT) indicated that Ce sites at the interface preferentially adsorbed H₂O, thereby isolating H₂O from Co active sites. Simultaneously, these sites effectively activated surface lattice oxygen by weakening the Co³⁺-O bond, thereby promoted oxygen migration rates. Combined with in situ diffuse-reflectance Fourier transform infrared spectroscopy (in situ DRIFTS) results, it was found that this interface could effectively promote surface hydroxyl removal and dynamic self-regeneration of interfacial sites in an O₂ atmosphere, reducing the accumulation of toxins such as carbonates. Moreover, the La₂O₃-CeO₂@Co₃O₄ catalyst exhibited excellent thermal stability. This work underscored the critical importance of multi-component interfacial structures in governing catalytic durability and offered a feasible strategy for designing high-performance industrial catalysts under humid conditions.