The selective electrochemical reduction of CO2 to CO in water by molecular catalysts of the type M(bpy)(CO)3Cl (M = Mn, Re), and Co(pthalocyanine) incorporated into multi-walled carbon nanotubes (MWCNT) was investigated. Current densities in excess of 5 mA/cm2 and selectivities (FECO) of 99% were achieved at -0.56 V vs. RHE in CO2 saturated aqueous KHCO3 solutions. Supporting these catalysts on MWCNTs increases current densities, decreases overpotential, retains selectivity for reduction of CO2 to CO, and allows operation in water at pH = 7.3 compared to the molecular catalysts in organic solvents. Recent studies of how these catalysts are aimed at answering the following questions: (1) How do these catalysts interact with graphitic materials such as MWCNTs? (2) Is there strong electronic coupling between the catalysts and the electrode material? (3) How do strong electric fields created by adsorption of the catalysts onto MWCNTs combined with high supporting electrolyte concentrations affect catalysis? Recent results of X-ray Absorption Near Edge Spectroscopy (XANES) and Extended X-ray Absorption Fine Structure (EXAFS) studies will be presented to attempt to answer the key questions concerning the interfacial properties of supported molecular catalysts.

XANES and EXAFS studies of molecular catalysts at graphitic electrode interfaces

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.