Abstract.
The surface region of sulfate aerosols (supercooled aqueous concentrated sulfuric acid solutions) is the likely site of a number of important heterogeneous reactions in various locations in the atmosphere, but the surface region ionic composition is not known. As a first step in exploring this issue, the first acid ionization reaction for sulfuric acid, H2SO4 + H2O → HSO4 − + H3O+, is studied via electronic structure calculations at the Hartree–Fock level on an H2SO4 molecule embedded in the surface region of a cluster containing 33 water molecules. An initial H2SO4 configuration is selected which could produce H3O+ readily available for heterogeneous reactions, but which involves reduced solvation and is consistent with no dangling OH bonds for H2SO4. It is found that at 0 K and with zero-point energy included, the proton transfer is endothermic by 3.4 kcal/mol. This result is discussed in the context of reactions on sulfate aerosol surfaces and, further, more complex calculations.
Abstract.
The surface region of sulfate aerosols (supercooled aqueous concentrated sulfuric acid solutions) is the likely site of a number of important heterogeneous reactions in various locations in the atmosphere, but the surface region ionic composition is not known. As a first step in exploring this issue, the first acid ionization reaction for sulfuric acid, H2SO4 + H2O → HSO4 − + H3O+, is studied via electronic structure calculations at the Hartree–Fock level on an H2SO4 molecule embedded in the surface region of a cluster containing 33 water molecules. An initial H2SO4 configuration is selected which could produce H3O+ readily available for heterogeneous reactions, but which involves reduced solvation and is consistent with no dangling OH bonds for H2SO4. It is found that at 0 K and with zero-point energy included, the proton transfer is endothermic by 3.4 kcal/mol. This result is discussed in the context of reactions on sulfate aerosol surfaces and, further, more complex calculations.
การแปล กรุณารอสักครู่..
