A Heterogenized Copper Phenanthroline System to Catalyze the Oxygen Reduction Reaction

Cornelis J M van der Ham; Damy N H Zwagerman; Longfei Wu; Jan P Hofmann; Dennis G H Hetterscheid

doi:10.1002/celc.202101365

A Heterogenized Copper Phenanthroline System to Catalyze the Oxygen Reduction Reaction

ChemElectroChem. 2022 Feb 11;9(3):e202101365. doi: 10.1002/celc.202101365. Epub 2022 Feb 2.

Authors

Cornelis J M van der Ham¹, Damy N H Zwagerman¹, Longfei Wu^{2

3}, Jan P Hofmann^{2

4}, Dennis G H Hetterscheid¹

Affiliations

¹ Leiden Institute of Chemistry P.O. Box 9502 2300 RA Leiden the Netherlands.
² Laboratory for Inorganic Materials and Catalysis De partment of Chemical Engineering and Chemistry Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven The Netherlands.
³ Current address: Inorganic Chemistry and Catalysis, Department of Chemistry Utrecht University Universiteitsweg 99 3584 CG Utrecht The Netherlands.
⁴ Current address: Surface Science Laboratory, Department of Materials and Earth Sciences Technical University of Darmstadt Otto-Berndt-Strasse 3 64287 Darmstadt Germany.

Abstract

Upon the electrochemical reduction of an in situ generated 5-diazo-1,10-phenanthroline ion, phenanthroline was covalently attached to a gold electrode. The grafted molecules act as a ligand when brought in contact with a copper-containing electrolyte solution. As the ligands are limited in spatial movement, the exclusive formation of the active species with only one phenanthroline ligand coordinated was expected. The in situ generated complexes have been investigated for activity in the oxygen reduction reaction, for which an overpotential of 800 mV is observed. During catalysis, initially a thick copper layer is formed on top of an organic layer that is still present on the gold surface. Upon deterioration of the organic layer underneath the copper over time, the amount of copper on the electrode and thereby the electrocatalytic activity decreases.

Keywords: Copper; Diazocoupling; Electrochemistry; Oxygen Reduction; Surface Immobilization.