Several factors can lead to the decreased efficiency of a catalyst:
Catalyst Poisoning: Certain substances can bind irreversibly to the active sites of a catalyst, rendering it less effective. Common poisons include sulfur and lead. Sintering: High temperatures can cause catalyst particles to agglomerate, reducing the surface area available for reactions. Coking: The deposition of carbonaceous materials on a catalyst surface can block active sites and hinder reactions. Leaching: In liquid-phase reactions, the active components of a catalyst can dissolve into the reaction medium, leading to a loss of catalytic activity. Thermal Degradation: Prolonged exposure to high temperatures can alter the physical and chemical properties of a catalyst, reducing its effectiveness. Deactivation by Sintering: High temperatures can cause the active metal particles to agglomerate, reducing the surface area and active sites available for the reaction.
