Abstract: The mechanism of the influence of H2O on the adsorption of SO2 and NO on γ-Al2O3 was investigated by molecular simulation and experimental investigation. The adsorption structure of γ-Al2O3 (110C) surface was constructed, and the adsorption models for H2O, SO2, NO molecules on (110C) surface were established to determine the optimized adsorption structure. It was found that there was obvious electron transfer between adsorbate and (110C) Al site by charge density and partial density of states, resulting in the formation of stable adsorption structure. H2O occupied Al3c and O3c sites through molecular adsorption and dissociation adsorption; SO2 was mainly adsorbed at Al3c and Al4c sites, while NO interacted with the Al4c sites and needed to be oxidized at the O3c sites. Therefore, there is a competitive adsorption among H2O, SO2, NO at Al3c and O3c sites on the γ-Al2O3 (110C) surface. The experimental results were basically consistent with the theoretical analysis of molecular simulation. H2O is not conducive to the adsorption of SO2 and NO on γ-Al2O3.

Key words: molecular simulation, water, alumina, sulfur dioxide, nitric oxide