Gas Adsoption Quantitive Calculation And Molecular Dynamics Simulation Of Ionic Liquids

Adsorption of carbon monoxide on different Ag⁺-exchange sites ofAg(I)-ZSM-5zeolite has been investigated using density functionaltheory. The coordination and local geometry of the Ag⁺ion inAg(I)-ZSM-5as well as adsorption structures and energies of COadsorbed on these sites are explored extensively. The calculated resultsshow that the Ag-O coordination number of two is strongly preferredbefore and after CO adsorption. The Ag-O bond lengths are in a broadrange of2.2-2.9, and the Ag-C bond lengths for CO adsorbed onAg(I)-ZSM-5zeolite are calculated to be2.0-2.2. Both Ag-O and Ag-Cbond lengths for CO-Ag(I)-ZSM-5complex are longer than those forCO-Cu(I)-ZSM-5complex. On zeolite, which has been exchanged by Alatom, the calculated adsorption energy of CO adsorbed on the I2sites isbetween28.5and29.6kcal/mol, and that on the Z5, Z6, M5and M6sites containing one Al atom on the T position is between11.3and18.9kcal/mol whereas the calculated adsorption energy of CO adsorbed on theM7site containing one Al atom is19.9kcal/mol. The introduction of thetwo Al atoms to the Ag⁺-exchange site results in a reduction of COadsorption energy. In general, the adsorption energy of CO onAg(I)-ZSM-5is lower than that on Cu(I)-ZSM-5. The predictedcoordination of the Ag⁺ion, bond lengths of Ag-O and Ag-C are inaccord with available experimental results.Through adsorption calculation of NO, NO₂, N₂O and H₂O onCu(I)-ZSM-5and Fe-ZSM-5, we can get that if catalysts are different, theadsorption energy of gas is also different, even though the same kind ofgas, if adsorption orientation is different, the adsorption energy is alsodifferent.By using molecular dynamics method, I optimize the structure ofBMIMBF4, After optimization, the B-CR length is3.479, which is inaccordance with literature result.