Multiphase Chemistry of Pyruvic Acid Under Atmospherically Relevant Conditions

Abstract:

Chemistry in the natural environment proceeds in multiple phases and is subject to effects from atmospheric constituents and conditions. This presentation will use pyruvic acid as a case study to demonstrate the complexity of atmospheric multiphase chemistry. The photophysics and photochemistry of pyruvic acid proceeds on different potential energy surfaces with different reaction mechanisms, rates, and products in gas versus the aqueous phase. While the gas phase reaction generally decreases the complexity of products, the aqueous chemistry creates higher molecular weight, surface-active compounds. The studies presented involve a combination of laboratory studies that focus on the photochemistry of pyruvic acid in both the gas and aqueous phases. Further, experiments in an environmental simulation chamber (CESAM) that follow the photochemistry chemistry of pyruvic acid under atmospherically relevant conditions will be presented to highlight the effect of pressure, oxygen, relative humidity, and phase on the photochemistry of pyruvic acid. The results provide new input for atmospheric chemistry models that is required to better describe the behavior of α-keto acids in the environment.