What are the Common Causes of Catalyst Deactivation?
Catalyst deactivation can occur due to several mechanisms:
1. Poisoning: This occurs when impurities or reaction by-products chemically bind to the active sites, rendering them inactive. Common poisons include sulfur, chlorine, and heavy metals. 2. Fouling: Deposition of carbonaceous materials or other solid residues on the catalyst surface can block active sites. 3. Sintering: Exposure to high temperatures can cause the agglomeration of metallic particles, reducing the surface area available for catalysis. 4. Leaching: Soluble components of the catalyst may dissolve into the reaction medium, especially in liquid-phase reactions. 5. Thermal Degradation: Prolonged exposure to high temperatures can cause structural changes in the catalyst.
