Conductive Covalent Organic Frameworks of Polymetallophthalocyanines as a Tunable Platform for Electrocatalysis

Abstract

Developing an electrocatalyst platform that can control the interplay among activity, selectivity, and stability at atomic precision remains a grand challenge. Here, we have synthesized highly crystalline polymetallophthalocyanines (<i>p</i>MPcs, M = Fe, Co, Ni, and Cu) through the annulation of tetracyanobenzene in the presence of transition metals. The conjugated, conductive, and stable backbones with precisely installed metal sites render <i>p</i>MPcs a unique platform in electrochemical catalysis, where tunability emerges from long-range interactions. The construction of <i>p</i>CoNiPc with a Co and Ni dual-site integrates the advantageous features of <i>p</i>CoPc and <i>p</i>NiPc in electrocatalytic CO₂ reduction through electronic communication of the dual-site with an unprecedented long atomic separation of ≥14 chemical bonds. This integration provides excellent activity (current density, <i>j</i> = -16.0 and -100 mA cm^-2 in H-type and flow cell, respectively), selectivity (CO Faraday efficiency, FE_CO = 94%), and stability (>10 h), making it one of the best-performing reticular materials.