Metal doping can be achieved through various methods, including:
1. Impregnation: The catalyst support is soaked in a solution containing the dopant metal precursor, followed by drying and calcination. 2. Co-precipitation: The dopant and catalyst precursors are co-precipitated from a solution, followed by filtration, drying, and calcination. 3. Ion Exchange: Metal ions are exchanged with ions on the catalyst support, followed by appropriate post-treatment steps.