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.