<p>This study investigates the inhibitory effects and underlying mechanisms of perfluorohexanone (C₆F₁₂O) on coal spontaneous combustion (CSC), in comparison with conventional chloride salt inhibitors. A combined experimental and theoretical strategy was adopted, including gas chromatography, non-isothermal oxidation (NIO), electron spin resonance (ESR), Fourier transform infrared (FTIR) spectroscopy, and quantum chemical calculations. The results show that C₆F₁₂O at a 2 mass% dosage significantly outperforms inorganic chloride salts in both inhibition efficiency and effective temperature range. Coal treated with C₆F₁₂O exhibits a markedly higher crossing point temperature (CPT), alongside substantial reductions in marker gas emissions (CO, C₂H₄) and oxygen consumption. At the microstructural level, coal treated with C₆F₁₂O shows a negligible increase in the g-factor (only 0.031%) and a 39.9% reduction in radical concentration relative to raw coal, while the generation of aliphatic (-CH₃, -CH₂-) and oxygen-containing functional groups is greatly suppressed. Mechanistically, while CaCl₂ mainly functions as a physical barrier to isolate oxygen and retain moisture below 80 ℃, C₆F₁₂O fundamentally terminates radical chain reactions. Quantum chemical calculations further confirm that radicals derived from C₆F₁₂O decomposition can efficiently scavenge key oxidative radicals produced during coal oxidation. This study verifies that C₆F₁₂O possesses superior inhibitory performance on CSC and can effectively reduce the risk of coal spontaneous fires.</p>