Adsorption of SO2 and NO2 on ZrO2 (1 1 0) Surface: Density Functional Theory and Molecular Dynamic Simulation Studies

In order to save the environment, there is an urgent need for control measures due to the rapidly rising concentration of greenhouse gases in the atmosphere. Density functional theory (DFT) and molecular dynamic simulation investigations are used in this study to examine the adsorption characteristics of SO2 and NO2 on zirconia surface. Several global reactivity parameters are analyzed as part of the DFT calculations, including the energy of the highest occupied molecular orbital (EH), the energy of the lowest unoccupied molecular orbital (EL), the separation energy (∆E), electronegativity (χ), ionization potential (I), electron affinity (A), hardness (η), softness (σ), the global electrophilicity index (ω), the nucleophilicity (ε), the energy of back donation (∆Eb-d) and fraction of electron(s) transfer (∆Nmax). The adsorption/binding energies that come from the interaction between the molecules and the ZrO2 (1 1 0) surface are taken into account in the molecular dynamic simulation. Compared to NO2 (∆E = 6.424 eV), the zirconia surface is substantially more sensitive to SO2 (∆E = 5.415 eV) capture, according to the DFT data. The findings of the quenched molecular dynamic simulations also showed that SO2 (Eads = -66.23 kcal/mol) is more likely to adsorb on zirconia surface than NO2 (Eads = -57.50 kcal/mol), despite the fact that both molecules obey the physical adsorption mechanism. S for SO2 and N for NO2 respectively bond to the ZrO2(1 1 0) surface due to the two molecules’ favorable orientation, which is parallel to the surface with angles pointing upward. Zirconium oxide can thus be used as an effective adsorbent for the removal of SO2 and NO2 gases from air environments as a result of these discoveries.