Highly selective and efficient electroreduction of CO ₂ in water by quaterpyridine derivative?based molecular catalyst noncovalently tethered to carbon nanotubes

A disubstituted quaterpyridine based cobalt complex non-covalently tethered to multiwalled carbon nanotube (MWCNT) substrate, forming a hybrid catalyst, Co-qpyCOOH/CNT, catalyzed the conversion of CO2 CO under aqueous conditions. At an optimal and uniform loading, it exhibited remarkable catalytic activity, near-exclusive selectivity, high stability towards formation CO. mere cathodic potential ?0.65 V versus RHE (? = 0.54 V), achieved partial current density ?6.7 mA/cm2 F.E.CO 100%. In addition, with 20 h stable operation, hydrogen evolution remained practically undetected. Its structure due noncovalent immobilization on MWCNT imparted intrinsic activity much-needed in performance whereas ?COOH groups may stabilize intermediates by acting as H-bond donors, promoting activity. Tethering conductive solid substrate tuning second sphere coordination played important role its achieve desired reduction product selectivity