The Harm of NOx and Its Emission

Nitrogen oxide (NOx) refers to a compound composed only of nitrogen and oxygen, including a variety of compounds, such as nitrogen monoxide (N2O), nitric oxide (NO), nitrogen dioxide (NO2), nitrogen trioxide (N2O3), nitrogen tetroxide (N2O4) and nitrogen pentoxide (N2O5). In addition, there are nitrosyl azide (N4O) and nitrogen trioxide (NO3). Trinitroamine N(NO2)3 is also a compound composed only of nitrogen and oxygen elements, but it is not an oxide in the strict sense. Except for nitrous oxide and nitrogen dioxide, other nitrogen oxides are unstable.