为探究CO₂、O₂在煤体中的吸附特性及扩散规律，采用巨正则系综蒙特卡洛和分子动力学方法对CO₂、O₂气体在不同摩尔比、温度和压力下煤体中的吸附及扩散过程进行了模拟研究。结果表明：①在煤体中CO₂呈簇状聚合分布，O₂呈点状分散分布；在同等条件下，吸附量、等量吸附热、平均质量密度、吸附选择性均为CO₂大于O₂；随着CO₂的摩尔比增加，CO₂的吸附量、等量吸附热和扩散系数呈增加趋势。② CO₂的质量密度随摩尔分数的增加而增大，但CO₂的摩尔分数过量增加，会导致O₂扩散系数增大；随着压力增大，CO₂的吸附选择性系数从7.67降低至3.69。③ O₂的吸附性弱于CO₂，扩散呈降低趋势，而CO₂的扩散呈升高趋势；温度升高会弱化煤体对CO₂和O₂气体的吸附能力，但对O₂和CO₂扩散有显著促进效果，较高的温度有助于两气体的扩散，加速从煤体中脱附，扩散系数呈升高趋势。研究结果可为煤自燃等灾害事故的防治提供参考。

In order to investigate the adsorption characteristics and diffusion law of CO₂ and O₂ in coal, the adsorption and diffusion processes of CO₂ and O₂ in coal at different molar ratios, temperatures and pressures were simulated using the grand canonical system Monte Carlo and molecular dynamics methods. The findings indicated that: ① CO₂ was distributed in clustered aggregation and O₂ was distributed in point-like dispersion in coal. Under identical conditions, the adsorption quantity, equivalent adsorption heat, average mass density, and adsorption selectivity were CO₂>O₂. ② With the increase of the molar ratio of CO₂, the adsorption amount, the equivalent adsorption heat, and the diffusion coefficient of CO₂ exhibited a tendency to increase. The mass density of CO₂ increased with the increase of the mole fraction, but an excessive increase in the mole fraction of CO₂ results in an increase in the O₂ diffusion coefficient. With increasing pressure, the adsorption selectivity coefficient of CO₂ decreases from 7.67 to 3.69. ③ The adsorption of O₂ is weaker than that of CO₂, and the diffusion of O₂ shows a decreasing trend, while the diffusion of CO₂ shows an increasing trend. An increase in temperature has a detrimental effect on the adsorption capacity of coal for CO₂ and O₂. However, the diffusion of O₂ and CO₂ exerts a significant promotional influence, with a higher temperature facilitating the diffusion of the two gases and accelerating the desorption from coal. Consequently, the diffusion coefficient demonstrates an increasing trend. The findings of this study may serve as a valuable reference for the prevention and control of spontaneous coal combustion and other related disasters.