Defect-Engineering-Enabled Efficient CO Oxidation in Fire-Generated Smoke: Mechanistic Insights into Wide-Temperature Adaptive La-Doped MOF-Derived CeO₂/CuO Catalysts

Driven by the urgent demand for efficient CO elimination from fire-derived toxic smoke, CuO coupled with a redox-active CeO₂ support and La promoter has attracted attention as a robust and low-cost composite-oxide catalyst for CO oxidation under harsh conditions. In this study , the effect of La/Ce molar ratios and doping strategies on the structure and catalytic properties of metal-organic framework (MOF)-derived catalysts were systematically investigated, aiming to construct dual-metal synergistic systems with boosted CO oxidation efficiency. By precisely regulating synthesis parameters (temperature, solvent, and precursor concentration), MOF-derived catalysts with tailored crystal frameworks, hierarchical pore structures, and optimized surface chemistry were successfully fabricated. The physicochemical properties and catalytic behaviors were correlated via complementary characterizations, including X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and density functional theory (DFT) calculations were combined to reveal the intrinsic catalytic mechanisms. This integrated strategy clarified how dual-metal synergy governs CO adsorption, activation, and conversion over a broad temperature range. Ultimately, this work provides a rational design strategy for high-performance CO oxidation catalysts and highlights the potential of La-doped MOF-derived CeO₂/CuO catalysts for fire-smoke purification.