气体与煤表面吸附作用的量子化学研究

Quantum chemistry study on adsorption of gases on coal surface

选用褐煤、次烟煤、高挥发分烟煤、低挥发分烟煤和无烟煤5种煤表面结构模型,采用量子化学半经验方法INDO,从分子水平描述了CO、O2、H2O(g)、CO2、CH4和H2等6种气体在煤表面的吸附作用,计算了气体在煤表面的吸附能、吸附距离、吸附作用键级和净电荷变化等微观参数,用Morse函数拟合了气体与煤表面的结合能曲线,得到了气体吸附作用强弱次序为:CO和O2最强,H2O和CO2次之,CH4和H2最弱。

Lignite, sub-bituminous coal, high volatile bituminous coal, low volatile bituminous coal and anthracite were chosen as models of coal surface, and the adsorption of six kinds of gases on coal surface were discussed, which were CO, O2, H2O（g）, CO2, CH4 and H2. The adsorption was described on the molecular level using the semi-empirical quantum chemistry intermediate neglect of differential overlap （INDO） method. The corresponding microscopic parameters, such as adsorption energies, adsorption distances, adsorption bond orders and changes of net charge of gases on coal surface were calculated. The curves of binding energies between gases and coal surface were fitted well using the Morse function. It was indicated that the adsorption of CO and O2 on coal surface was the strongest, the next was H2O and CO2, and the weakest was CH4and H2.