Effects of Nitrates on the Heterogeneous Reaction of Carbonyl Sulfide on Model Aerosols

Abstract

The heterogeneous reaction of carbonyl sulfide (COS) on hematite particles in the presence of nitrate was investigated by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). For sodium nitrate-containing samples, the hematite sample containing NaNO3 with mass fraction of 4% gave the highest reaction rate, which was about 5 times higher than that of hematite. For the particles containing nitrate at the same mass fraction (24%) the reactivity in descending order was α-Fe2O3/KNO3, α-Fe2O3/NaNO3, α-Fe2O3/NH4NO3 and α-Fe2O3. No uptake of COS was observed for the pure NaNO3, KNO3 and NH4NO3 samples. These results indicate that the added nitrate increased the COS conversion ability of α-Fe2O3 particles.