煤表面对多种气体分子混合吸附的微观机理

应用量子化学密度泛函理论,在6-311 g水平上对建立的吸附模型进行全优化.结果表明,煤的表面能够与多组分气体发生混合吸附.煤表面吸附氧、氮和二氧化碳分子组成的吸附态中,氧分子和氮分子在煤表面的侧链吸附,CO2则在苯环的上方.煤表面氨基上的C原子和N原子的电子向氧分子中的氧原子转移.煤表面吸附了二氧化碳和氮分子,氧分子所得的电子减少,表明如果煤表面吸附其它种类分子,则削弱了吸附氧的作用.吸附后O2的频率变化较大,N2和CO2的频率变化很小.煤表面与矿井采空区各种气体发生吸附时的亲和顺序为:氧气>水>二氧化碳>氮气>一氧化碳>甲烷.

Microcosmic mechanism of coal surface to multiple gas molecules mixed adsorption

Applied quantum chemistry density functional theory,it had carried on the entire optimization to the establishment adsorp- tion model at the 6-311g level.The results show that the coal surface can have mixed adsorption with the multi-component gas.In the adsorption state of coal surface having adsorption with oxygen molecule,nitrogen molecule and carbon dioxide molecule,oxygen mole- cule and nitrogen molecule are absorbed in the coal surface side chain,and the CO_2 is absorbed above the benzene ring.The electron- ics of the C atom and the N atom on the coal surface amino transfer to oxygen atom in the oxygen molecule.Carbon dioxide and nitrogen molecule are absorbed in the coal surface,and the oxygen molecule gains fewer electronics.It shows that the effect of adsorption oxygen is weakened when the other kinds of molecules are absorbed in the coal surface.After adsorption,the frequency of O_2 changes greatly, but the frequency of N_2 and CO_2 changes very small.The affinity order is O_2>H_2O>CO_2>N_2>CO>CH_4,when the coal surface having adsorption with all kinds of gas in the mine goaf.