PII.147 NOx Reduction with Urea and Ammonia: Insights from Reactive Molecular Dynamics Study

Resumo

Nitrogen oxides (NOx) are extremely harmful to the environment and to human health, being formed mainly from the reaction between atmospheric nitrogen (N₂) and oxygen (O₂) in processes involving combustion. Primary and secondary control systems to reduce NOx emissions have been implemented and those based on Selective Catalytic Reduction (SCR) technology are the most efficient. The SCR technology uses urea as a reducing agent in the presence of a catalyst to convert NOx into molecular nitrogen (N₂) and water (H₂O). In this study, we use the ReaxFF force field in molecular dynamics simulations to investigate NOx reduction in the gas phase in order to understand the molecular mechanism of the reaction. The results indicate that the NH₂ species plays a crucial role in the reduction of NOx with ammonia, since the reaction between NH₂ and NO results in the formation of nitrosamine (NH₂NO), which decomposes into N₂ and H₂O. However, our simulations revealed an alternative pathway for the formation of N₂ from the reaction between HON and NO.