From Molecules to Porous Materials: Integrating Discrete Electrocatalytic Active Sites into Extended Frameworks.

Metal-organic and covalent-organic frameworks can serve as a bridge between the realms of homo- and heterogeneous catalytic systems. While there are numerous molecular complexes developed for electrocatalysis, homogeneous catalysts are hindered by slow catalyst diffusion, catalyst deactivation, and poor product yield. Heterogeneous catalysts can compensate for these shortcomings, yet they lack the synthetic and chemical tunability to promote rational design. To narrow this knowledge gap, there is a burgeoning field of framework-related research that incorporates molecular catalysts within porous architectures, resulting in an exceptional catalytic performance as compared to their molecular analogues. Framework materials provide structural stability to these catalysts, alter their electronic environments, and are easily tunable for increased catalytic activity. This Outlook compares molecular catalysts and corresponding framework materials to evaluate the effects of such integration on electrocatalytic performance. We describe several different classes of molecular motifs that have been included in framework materials and explore how framework design strategies improve on the catalytic behavior of their homogeneous counterparts. Finally, we will provide an outlook on new directions to drive fundamental research at the intersection of reticular-and electrochemistry.