In recent decades, nanocluster research has rapidly advanced. Though Cu nanoclusters are relatively new to the field, their use in chemical catalysis has expanded the potential applications of these materials. The reactivity of Cu nanoclusters is primarily determined by their precisely controlled structural architecture and surface-to-volume ratio. However, these factors are prone to change, significantly impacting their catalytic properties. Therefore, a comprehensive understanding of these parameters is crucial to guide future research efforts and develop new Cu nanoclusters with broader applications.