Catalytic converters reduce the amount of which substance in car exhaust?

Catayltic converters are designed to minimize harmful emissions from car exhaust, particularly focusing on reducing pollutants that can cause respiratory issues and contribute to environmental problems. One of the primary functions of catalytic converters is to convert carbon monoxide (CO), a toxic gas produced during fuel combustion, into less harmful substances such as carbon dioxide (CO2).

While carbon dioxide is a greenhouse gas associated with climate change, catalytic converters mainly target carbon monoxide due to its immediate health risks. The reduction of carbon monoxide in emissions is a significant benefit of using catalytic converters, contributing to cleaner air and improved public health.

The other substances listed in the options—NOx (nitrogen oxides), CO2, and O2—are also present in exhaust emissions, but catalytic converters do not specifically function to reduce these as their main objective. NOx is typically reduced through a different mechanism or in vehicles equipped with specific technologies. CO2 is a product of combustion rather than a pollutant targeted for reduction. Oxygen is not a pollutant produced during combustion and is not reduced by catalytic converters.