1. Structural Modification This involves changing the physical structure of the catalyst, such as: - Particle Size Reduction: Smaller particles have a higher surface area-to-volume ratio, which can enhance catalytic activity. - Support Materials: Using different support materials like silica or alumina can affect the dispersion and stability of the active phase.
2. Chemical Modification Altering the chemical makeup of the catalyst can be done through: - Doping: Introducing small amounts of another element to modify electronic properties and improve performance. - Surface Functionalization: Adding functional groups to the catalyst surface to improve reactant adsorption.
3. Promoters and Inhibitors - Promoters: Substances added to enhance the catalytic activity or selectivity. For example, adding potassium to iron catalysts in ammonia synthesis. - Inhibitors: Substances that selectively poison or deactivate unwanted catalytic sites, thus improving selectivity.
