How does catalyst poisoning affect catalytic activity?
Catalyst poisoning occurs when impurities bind to the active sites, reducing the catalyst's effectiveness. In the case of ammonia synthesis over iron catalysts, the presence of sulfur compounds leads to a significant drop in catalytic activity. Experimental studies show that even trace amounts of sulfur can decrease the reaction rate by more than 50%. This highlights the necessity of using high-purity reactants and implementing strategies to mitigate poisoning effects.
