Dopants can be classified based on their nature and the effect they have on the catalyst: 1. Metal Dopants: Elements like platinum, palladium, and gold are often used to enhance catalytic activity and selectivity. 2. Non-metal Dopants: Elements such as nitrogen, sulfur, and phosphorus can modify the electronic properties and surface chemistry of catalysts. 3. Oxide Dopants: Metal oxides such as TiO2, Al2O3, and SiO2 can improve the thermal stability and mechanical strength of catalysts.
