What are the Common Mechanisms of Catalyst Deactivation?
1. Poisoning: This occurs when impurities or reactants bind strongly to the active sites of the catalyst, rendering them inactive. Common poisons include sulfur, phosphorus, and heavy metals.
2. Fouling: Fouling involves the physical deposition of undesired materials, such as coke or polymers, on the catalyst surface. This can block active sites and pores, severely impacting performance.
3. Sintering: Sintering, also known as thermal degradation, involves the agglomeration of catalyst particles at high temperatures, leading to a reduction in surface area and active sites.
4. Leaching: This mechanism is more common in liquid-phase reactions where the active components of the catalyst dissolve into the reaction medium, thereby deactivating the catalyst.
