为了明确硫化氢(H₂S)在煤中吸附扩散的微观动力学机理，揭示不同温度、压力对煤吸附H₂S分子吸附扩散特性的影响机制，基于巨正则蒙特卡罗(GCMC)、分子动力学(MD)和密度泛函理论(DFT)方法，利用Material Studio软件研究了温度在273.15～313.15 K、压力1～1 000 kPa时H₂S在气肥煤大分子模型中的吸附扩散特征。结果表明：温度由273.15 K升至313.15 K时，H₂S的饱和吸附量由38.34 mL/g降至31.85 mL/g，降低了16.93%，当压力为1 kPa时，温度对吸附量的影响最为敏感。温度为293.15 K时，压力由1 kPa升至1 000 kPa时，最可几相互作用能由−39.391 kJ/mol升至−34.301 kJ/mol，随着压力的增加，最可几相互作用能先快速增加，后缓慢增加。在吸附H₂S过程中，H₂S的等量吸附热在36.63～41.43 kJ/mol内，为物理吸附，等量吸附热随着吸附量的增加呈现出负指数变化；H₂S的吉布斯自由能ΔG为−3.57～−24.57 kJ/mol，吸附熵ΔS为−0.126～−0.194 8 kJ/(mol·K)，随吸附量升高ΔG和ΔS的绝对值线性降低，H₂S的吸附自发性和系统的混沌程度均降低。H₂S与气肥煤的相互作用能为−492.47～−3 390.95 kJ/mol，以范德华能为主，占总能量的58.67%，以静电能为辅，占41.33%，随着吸附量的增加，相互作用能绝对值增加，吸附量与相互作用能的变化具有一致性。H₂S与羧基的相互作用最强，羟基次之，H₂S在—OH、—COOH、—C=O周围存在双层吸附。温度由273.15 K升至313.15 K，H₂S分子的扩散系数由1.066×10⁻¹⁰ m²/s升至2.025×10⁻¹⁰ m²/s，温度升高会导致原本闭合的孔吼孔道打开，增加裂隙的连通性，温度升高，增加H₂S分子平均自由程，使得H₂S扩散能力增强，H₂S扩散活化能为11.206 kJ/mol。H₂S相对体积分数分布呈现多峰结构，H₂S在气肥煤大分子模型中呈层状结构分布。H₂S的极限吸附热为42.898 kJ/mol，H₂S与煤体上—OH、—COOH、—C=O活性基团产生氢键作用，H₂S在吸附初期存在微弱的化学吸附。

In order to clarify the microscopic dynamics mechanism of hydrogen sulfide (H₂S) adsorption and diffusion in coal, and to reveal the influence mechanism of different temperatures and pressures on the molecular adsorption and diffusion characteristics of coal adsorbed H₂S, based on the Giant Canonical Monte Carlo (GCMC), Molecular Dynamics (MD), and Density Functional Theory (DFT) methods, the adsorption-diffusion characteristics of H₂S in the gas-fertilized coal macromolecule model at temperatures ranging from 273.15 K to 313.15 K and pressures ranging from 1 to 1 000 kPa were investigated using Material Studio software. The results showed that the saturated adsorption of H₂S decreased from 38.34 mL/g to 31.85 mL/g at an increase in temperature from 273.15 K to 313.15 K, which is a 16.93% decrease. The effect of temperature on adsorption is most sensitive when the pressure is 1 kPa. The most significant interaction energy increased from −39.391 kJ/mol to −34.301 kJ/mol when the pressure was increased from 1 kPa to 1 000 kPa at a temperature of 293.15 K. With the pressure increased, the most significant interaction energy increased first rapidly and then slowly. During the adsorption of H₂S, the isocratic heat of adsorption of H₂S was in the range of 36.63−41.43 kJ/mol, which is a physical adsorption. The isocratic heat of adsorption showed a negative exponential change with increasing adsorption volume. The Gibbs free energy ΔG of H₂S was from −3.57 to −24.57 kJ/mol, and the entropy of adsorption ΔS was from −0.126 to −0.194 8 kJ/(mol·K). The absolute values of ΔG and ΔS linearly decreased with increasing adsorption amount, and the adsorption spontaneity of H₂S and the chaos of the system decreased. The interaction energy of H₂S with gas-fertilized coal was ranged from −492.47 to −3 390.95 kJ/mol, which was dominated by van der Waals’ energy accounting for 58.67% of the total energy, and supplemented by electrostatic energy accounting for 41.33%. As the adsorption capacity increased, the absolute value of interaction energy increased, and the changes in adsorption capacity and interaction energy were consistent. H₂S interacted most strongly with the carboxyl group, followed by the hydroxyl group. Double layer adsorption of H₂S occurred around —OH, —COOH, —C=O. The temperature was increased from 273.15 K to 313.15 K. The diffusion coefficient of H₂S molecules was increased from 1.066×10⁻¹⁰ m²/s to 2.025×10⁻¹⁰ m²/s, and the activation energy of diffusion was 11.206 kJ/mol. An increase in temperature can lead to the opening of previously closed pores and channels, increasing the connectivity of cracks. As the temperature rises, it increases the average free path of H₂S molecules, enhancing their diffusion ability. The limiting heat of adsorption of H₂S was 42.898 kJ/mol. The H₂S concentration distribution showed a multi-peak structure, and H₂S was distributed in a laminar structure in the gas-fertilized coal macromolecule model. H₂S had hydrogen bonding with —OH, —COOH, and —C=O reactive groups on the coal body, and there was a weak chemisorption of H₂S in the early stage of adsorption.