How Does a Catalytic Converter Make Exhaust Cleaner

Burns Unburned Exhaust Gases

The main purpose of an automotive catalytic converter is to burn unburned engine exhaust gases exiting a cars engine. Engine combustion is not an exact science; theore, during normal engine operation, there are small bits of unburned fuel that get pushed out a cars engine during the exhaust stroke of an engine cycle. When this happens, the unburned fuel flows down a cars exhaust pipe on its way to the car tail pipe, where it would get released into the outside air. A catalytic converter, which looks almost identical to a car muffler in shape and size, is filled with small charcoal-like pellets called catalyst which become super-heated as exhaust gas flows pas them. These super-heated pellets react with the unburned gas molecules in a cars exhaust and simply reburn them, turning them into simple water and carbon dioxide molecules.

Makes Unleaded Gasoline Use Mandatory

Cars equipped with catalytic converters must be operated with unleaded gasoline only. Unleaded gasoline, due to its absence of lead, is a much cleaner and environmentally-friendly fuel than leaded gasoline. Lead is toxic to the environment and toxic to human health. The catalyst material used in catalytic converters, usually consisting of small platinum-coated charcoal pellets, are highly-sensitive to lead-based gasoline and would quickly be ruined and rendered ineffective if exposed to leaded gas. Theore, catalytic converter-equipped cars are designed to run on unleaded gasoline only, a gasoline that is inherently cleaner and less toxic than leaded gasolines. So, not only do catalytic converters help to make engine exhaust gases cleaner, they automatically require the use of cleaner gasoline to begin with.

Retards Exhaust Gas Flow

Catalytic converters create a small amount of back pressure within a cars engine. This is due to the constrictive effects that a catalytic converter has on exiting engine exhaust gases; the charcoal pellets combined with the small exhaust tubing within a catalytic converter slows down the speed at which exhaust gases exit an engine. Due to this slowing down of engine exhaust gas flow, a cars engine has slightly more time in which to adequately combust, or burn, its air/fuel mixture, a process that results in slightly cleaner exiting engine exhaust gases.