Homogeneous and heterogeneous atmospheric ozonolysis of acrylonitrile on the mineral dust aerosols surface

Abstract

Acrylonitrile (ACN) is a highly toxic substance that exists widely in the environment. It can pollute the environment and endanger human health. VOCs prone to nucleation and heterogeneous reaction on the mineral dust aerosols surface. Based on the DFT calculation, the ozonolysis processes of ACN in homogeneous reactions, heterogeneous reactions on SixOy(OH)z clusters surface and heterogeneous reactions on (Al2O3)n clusters surface were studied in this paper. Ozone addition was the rate-determining step for ozonolysis of ACN with the rate constant of 2.03 × 10−18 cm3 molecule−1 s−1 at 298 K and 1 atm. Toxicity assessment showed that ozonolysis degradation effectively reduced the ecotoxicity of ACN. In this study, six kinds of non-metallic oxides SixOy(OH)z clusters and thirteen kinds of metal oxides (Al2O3)n clusters were selected to simulate the adsorption behavior of ACN adsorbed on different mineral dust aerosols surface. ACN-SixOy(OH)z cluster polymers formed hydrogen bond interactions, while ACN-(Al2O3)n cluster polymers mainly formed metallic bonds (Al-N), and they also had hydrogen bond interactions. The adsorption of SixOy(OH)z clusters and (Al2O3)n clusters did not change the reaction mechanisms for ozonolysis of ACN, but affected the reaction rate constant to varying degrees. In addition, it was found that the adsorption modes of mineral dust aerosols surface had no correlation with the rate constants for ozonolysis of ACN.