Abstract

In electrochemical CO2-conversion strategies, various transition metal-based molecular electrocatalysts are employed to reduce CO2 into products like CO and HCO2H, with H2 as a competitive side product. However, achieving selectivity towards HCO2H remains challenging, and suitable catalysts for the same are limited. Herein we report a normal and an abnormal protic-NHC-based Cp*Ir(III)-half sandwich complexes for catalytic CO2 electroreduction in an aqueous acetonitrile solvent. Both the catalysts predominantly produced HCO2H as the CO2-reduced product at an applied potential of –2.66 V vs Fc+/Fc with 5 % H2O as the proton source; however, the normal protic-NHC-bound complex achieved a Faradic efficiency (FE) of 86±4 %, while the complex with the abnormal protic-NHC ligand furnished FE up to 72±4 %. The protic proton of the protic NHC ligand in these complexes was proposed to participate in a proton relay process, facilitating generation of the crucial Ir–H intermediate, which reacts with CO2 to produce HCO2H through stabilization of the Ir–OCHO intermediate.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.