Thermal stress can affect catalysts in several ways:
1. Structural Degradation: Repeated cycles of heating and cooling can lead to the formation of cracks and other structural defects in the catalyst. These defects can reduce the surface area available for catalytic reactions, thereby lowering the catalyst's efficiency. 2. Phase Changes: Some catalysts may undergo phase changes at high temperatures, which can alter their active sites and make them less effective. 3. Deactivation: High temperatures can also lead to the sintering of metal particles on supported catalysts. Sintering reduces the dispersion of active metal sites, leading to deactivation. 4. Chemical Transformation: Prolonged exposure to high temperatures can cause chemical transformations in the catalyst material, resulting in a loss of catalytic activity.
