Proton/Electron Donors Enhancing Electrocatalytic Activity of Supported Conjugated Microporous Polymers for CO2 Reduction.

Abstract

Metal phthalocyanines (MePc) hold great promise in electrochemical reduction of CO2 to value-added chemicals, whereas the catalytic activity of MePc-containing polymers often suffers from a limited molecular modulation strategy. Herein, we synthesize an ultrathin conjugated microporous polymer sheath around carbon nanotubes by an ionothermal copolymerization of CoPc and H2 Pc via the Scholl reaction. Given the H2 Pc-mediated regulation in the synthesis, CoII metal is well preserved in the form of single atoms on the polymer sheath of the carbon nanotubes. With the synergistic effect of H2 Pc moieties as proton/electron donors, the composites can selectively reduce CO2 to CO with a high Faradaic efficiency (max. 97 % at -0.9 V) in broad potential windows, exceptional turnover frequency (97 592 h-1 at -0.65 V) and large current density (>200 mA cm-2 ). It is thus desirable to develop a family of heterogeneous polymerized MePc with molecularly regulating electrocatalytic activity.