Immobilized Molecular Wires on Carbon-Cloth ElectrodesFacilitate CO 2 Electrolysis

Conjugated molecular wires of rhenium bipyridine complexes were grown on flexible, lightweight, carbon-cloth electrodes through reductive diazonium electropolymerization. CO2 electrolysis studies reveal rapid (k(cat) similar to 40 s(-1)) and selective (Faradaic efficiency >99%) conversion to CO with turnover numbers (TON) per rhenium site reaching similar to 290?000 and catalytic currents (i(cat)) > 10 mA/cm(2). This represents over an 80-fold increase in activity relative to our prior graphite systems and an similar to 25-fold increase relative to the highest-performing immobilized rhenium bipyridine catalyst to date under analogous electrolysis conditions while maintaining prolonged activity. The high activity of these electrodes is explained by a mechanism initiated via electrochemical charging of the pi-conjugated backbone followed by anion dissociation, CO2 coordination, and protonation. As numerous metal-bipyridine complexes are known for a broad scope of electrocatalytic transformations, these integrated carbon-cloth devices are anticipated to serve as a platform for future studies.