Several catalytic methods are employed for CO removal:
1. [Three-Way Catalysts](https://) (TWCs): Utilized in automotive exhaust systems, they convert CO, hydrocarbons, and NOx into CO2, H2O, and N2 using catalytic materials like platinum, palladium, and rhodium. 2. [Water-Gas Shift Reaction](https://): Involves the reaction of CO with water vapor to produce CO2 and hydrogen (H2). Catalysts like iron oxide (Fe2O3) and chromium oxide (Cr2O3) are commonly used. 3. [Preferential Oxidation](https://) (PROX): Selectively oxidizes CO in the presence of hydrogen, using catalysts like gold or platinum on alumina (Al2O3). 4. [Adsorption](https://): Involves the use of materials like activated carbon or zeolites that adsorb CO onto their surfaces, which can then be desorbed and treated.
