14.1.6—Combustion pollutants and catalysts

Incomplete combustion can produce CO; high-temperature combustion forms NOx; unburned hydrocarbons can escape. These pollutants have different health and atmospheric effects.

A catalytic converter promotes redox reactions: CO and hydrocarbons are oxidised, while NOx is reduced to N₂. The catalyst changes rate and the exhaust composition controls performance.

2CO + 2NO → 2CO₂ + N₂ is a simplified three-way-converter reaction. It reduces CO and NO simultaneously but does not remove every environmental impact of fuel use.

CO is not simply “more CO₂”, and catalytic removal is not the same as preventing pollutant formation in the engine.