Catalyst deactivation occurs due to factors like sintering, poisoning, fouling, and thermal degradation. Sintering involves the agglomeration of catalyst particles, reducing active surface area. Poisoning occurs when impurities bind to active sites, rendering them inactive. Fouling is the deposition of unwanted materials on the catalyst surface. Regeneration involves processes to restore catalytic activity, such as calcination to remove fouling materials or chemical treatments to remove poisons.
