What is a gasoline car catalyst？

Gasoline vehicle catalyst usually refers to the catalytic substance used in the three-way catalytic converter installed in the gasoline vehicle exhaust system.

These catalysts are generally composed of platinum (Pt), palladium (Pd), rhodium (Rh) and other precious metals. Their role is to promote the chemical reaction of harmful gases in automobile exhaust, carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxides (NOx) into harmless carbon dioxide (CO₂), nitrogen (N₂), water (H₂O) and other substances, so as to reduce the pollution of gasoline vehicle exhaust to the environment.

For example, a normal running gasoline car, its engine combustion generated exhaust contains a lot of harmful gases. When the tail gas passes through the three-way catalytic converter, the catalyst will make CO react with O₂ to produce CO₂, HC react with O₂ to produce CO₂ and H₂O, and promote the conversion of NOx into N₂ and O₂. Through these chemical reactions, the emission of harmful gases is greatly reduced, so that the automobile exhaust meets the environmental protection standards.

Working principle of metal catalysts for gasoline vehicles

The metal catalysts used in gasoline vehicles are usually located in the three-way catalytic converter, and their working principle is mainly based on the following chemical reactions:

Oxidation of carbon monoxide (CO) and hydrocarbons (HC) :

The catalyst (usually platinum, palladium and other precious metals) promotes the reaction of CO with oxygen to produce carbon dioxide (CO₂), the reaction formula:

 2CO + O₂ → 2CO₂

Likewise, the HC reacts with oxygen to form CO₂ and water (H₂O), for example:

CₓHₙ + (x + n/4)O₂ → xCO₂ + (n/2)H₂O

Reduction of nitrogen oxides (NOx, mainly nitric oxide NO and nitrogen dioxide NO₂) :

Under the action of a catalyst, NOx reacts with carbon monoxide (CO), hydrocarbons (HC), or hydrogen (H₂) and is converted into harmless substances such as nitrogen (N₂) and water (H₂O).

For example, when the exhaust gas after gasoline combustion enters the three-way catalytic converter, the CO and HC in it are rapidly combined with oxygen under the catalysis of platinum and palladium, and converted into harmless CO₂ and H₂O discharge. At the same time, NOx also reacts with other components in the exhaust gas on the catalyst surface and is reduced to N₂, which effectively reduces the emission of harmful pollutants in the exhaust gas.