Identification of synergies in polyaniline supported cobalt polyphthalocyanine for efficient and selective CO₂...

Electrocatalytic CO₂ reduction reaction (eCO₂RR) to CO is a viable pathway for sustainable fuel generation, though obstacles like high activation energies and the competing hydrogen evolution reaction (HER) remain unresolved. To overcome these limitations, we engineered a self-supported PANI@CoPPc/CP electrode, combining polyaniline (PANI) with cobalt polyphthalocyanine (CoPPc) to boost eCO₂RR efficiency. Fabrication involved a straightforward two-step process: electropolymerizing PANI onto carbon paper (CP), followed by solvothermal deposition of CoPPc. The PANI matrix contributes a conductive π-conjugated framework and nitrogen-rich functionalities, which increase CO₂ adsorption, stabilize critical intermediates, and inhibit HER, whereas the CoN₄ active sites in CoPPc provide robust catalytic performance. Remarkably, PANI@CoPPc/CP affords a Faradaic efficiency for CO generation (FE_CO) of 99.2 % at -0.8 V vs reversible hydrogen electrode (RHE), a turnover frequency (TOF) value of 11,594 h^-1 at -1.10 V vs RHE, and exceptional stability. Operando attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy identifies the stabilization of *COOH and *CO intermediates, corroborating enhanced reaction kinetics. Additionally, the electrode's hydrophobic surface and porous architecture improve mass transport. This study not only presents a highly effective electrocatalyst for CO₂-to-CO conversion but also introduces a scalable approach for coupling molecular catalysts with conductive polymers, with potential applications across renewable energy systems.