Immobilization strategies for porphyrin-based molecular catalysts for the electroreduction of CO.

The ever-growing level of carbon dioxide (CO) in our atmosphere, is at once a threat and an opportunity. The development of sustainable and cost-effective pathways to convert CO to value-added chemicals is central to reducing its atmospheric presence. Electrochemical CO reduction reactions (CORRs) driven by renewable electricity are among the most promising techniques to utilize this abundant resource; however, in order to reach a system viable for industrial implementation, continued improvements to the design of electrocatalysts is essential to improve the economic prospects of the technology. This review summarizes recent developments in heterogeneous porphyrin-based electrocatalysts for CO capture and conversion. We specifically discuss the various chemical modifications necessary for different immobilization strategies, and how these choices influence catalytic properties. Although a variety of molecular catalysts have been proposed for CORRs, the stability and tunability of porphyrin-based catalysts make their use particularly promising in this field. We discuss the current challenges facing CORRs using these catalysts and our own solutions that have been pursued to address these hurdles.