Poisoning: Certain substances, known as
catalyst poisons, can bind strongly to the active sites, rendering them inactive. Common poisons include sulfur, phosphorus, and heavy metals.
Sintering: At high temperatures, metal particles on the catalyst surface can agglomerate, reducing the overall surface area and thus the number of active sites.
Coking: The formation of carbon deposits, often referred to as
coke, can block the active sites and hinder the catalyst's performance.
Leaching: In liquid-phase reactions, active components of the catalyst can dissolve into the reaction medium, leading to their loss from the solid catalyst structure.
Thermal Degradation: Prolonged exposure to high temperatures can cause changes in the catalyst's structure, making the active sites less effective or entirely inactive.
