Design Principles of Metal Phthalocyanine for Electrochemical CO2 Reduction: From Targeted Molecular Structures to Atomic-Level Active Sites.

The electrocatalytic reduction of carbon dioxide (CO2RR) to valuable chemical feedstocks using renewable electricity is a promising approach to circumventing climate change due to the overuse of fossil energy. However, the most critical mission is to design high active and economical electrocatalysts. Metal phthalocyanine (MPc)-based electrocatalysts have attracted extensive research due to their well-defined active sites and flexible structural tunability. Specifically, the structural features of MPcs are first introduced and then summarize the different catalytic mechanisms for different CO2RR products. Importantly, the two main modification strategies of axial and horizontal modulation of MPc-based electrocatalysts are highlighted and systematically summarized. Furthermore, the selectivity of different MPc-based electrocatalysts for CO2RR products is summarized. Finally, challenges and expectations of MPc-based electrocatalyst design and selection are proposed. This article aims to present a comprehensive overview of MPc-based electrocatalysts, expecting to further inspire the development of MPc-based electrocatalysts and provide new ideas for the rational design of efficient electrocatalysts.