A Stable and Conductive Metallophthalocyanine Framework for Electrocatalytic Carbon Dioxide Reduction in Water

Transformation of carbon dioxide to high value-added chemicals becomes a significant challenge for clean energy studies. Here a stable and conductive covalent organic framework was developed for electrocatalytic carbon dioxide reduction to carbon monoxide in aqueous solution. The cobalt(II) phthalocyanine catalysts are topologically connected via robust phenazine linkage into a two-dimensional tetragonal framework that is stable under boiling water, acid, or base conditions. The 2D lattice enables full π conjugation along x and y directions as well as π conduction along the z axis across the π columns. With these structural features, the electrocatalytic framework exhibits a faradaic efficiency of 96 %, an exceptional turnover number up to 320 000, and a long-term turnover frequency of 11 412 hour-1 , which is a 32-fold improvement over molecular catalyst. The combination of catalytic activity, selectivity, efficiency, and durability is desirable for clean energy production.