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

Metal phthalocyanines (MePc) hold great promises in electrochemical reduction of CO2 to value-added chemicals, whereas the catalytic activity of MePc-containing polymers often suffers from the limited molecular modulation strategy. Herein, we synthesize an ultrathin conjugated microporous polymer sheath around carbon nanotubes by an ionothermal copolymerization of CoPc and H2Pc via the Scholl reaction. Given the H2Pc-mediated regulation in synthesis, Co(II) metal is well preserved in form of single atoms on the polymer sheath of carbon nanotubes. With synergistic effect of H2Pc moieties as proton/electron donors, the composites can selectively reduce CO2 to CO with a high Faradic 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.