Removal of Odorous Vapors by Their Adsorption on Allophane and Its Molecular Orbital Mechanism Part II.Molecular Orbital Calculation

摘要

Ab initio/hybrid(ONIOM)method was used to simulate the formation of five-fold coordination Al in the pore region of allophane and adsorption of ammonia and formaldehyde on it.Calculation results showed that the five-fold coordination Al in the pore region is easily formed with evacuation or heating.By comparing the binding energy,ammonia adsorbed strongly to the five-fold coordination Al than formaldehyde.This finding is in good agreement with experimental results.One important result from bond order analysis obtained is that structure of formaldehyde becomes easily collapse after adsorbed on five-fold coordination Al.Therefore,Lewis acid site in the pore region of allophane has capability to adsorb and decompose small organic molecule such as formaldehyde.