How is nitrogen dioxide produced when fossil fuels are burnt?

Nitrogen dioxide (NO2) is produced during the combustion of fossil fuels primarily through the reaction of nitrogen in the air with oxygen at high temperatures. This process, known as thermal NOx formation, occurs in engines and power plants where combustion temperatures exceed 1,200 degrees Celsius (2,192 degrees Fahrenheit). Additionally, NO2 can also form from the oxidation of nitrogen monoxide (NO), which is generated during combustion. The resulting nitrogen oxides contribute to air pollution and can lead to health and environmental issues.