Coalescence can have both positive and negative effects on catalytic activity. On one hand, the merging of smaller particles can lead to a reduction in the overall surface area of the catalyst. Since the catalytic activity often depends on the available surface area for reactions to occur, this reduction can diminish the efficiency of the catalyst. On the other hand, in some cases, coalescence can lead to the formation of more stable structures that are less prone to deactivation over time.
