Electrocatalytic reduction of Molecular Oxygen with a Copper (II) Coordination Polymer

Abstract

Oxygen reduction at the polarized water/1,2‐dichloroethane (DCE) interface catalyzed by a Cu (II) coordination polymer (Cu–pol) was studied with two lipophilic electron donors ferrocene (Fc) and tetrathiafulvalene (TTF). The results of the ion transfer voltammetry and two‐phase shake flask experiments suggest proceeding of the catalytic reaction as proton‐coupled electron transfer reduction of oxygen to hydrogen peroxide and water. In this process, while the protons supplied from the aqueous phase, the electrons provided from the organic phase by the weak electron donor, Fc. The O2 molecule takes a superoxide structure with Cu–pol which resulted to hydrogen peroxide or water on reduction. Furthermore, the results revealed that the apparent rate constant of TTF + Cu‐pol is higher than that of Fc + Cu‐pol system due to the faster kinetic reaction of TTF with respect to Fc.

Hydrogen Evolution, Oxygen Evolution, and Oxygen Reduction at Polarizable Liquid|Liquid Interfaces

“…Biphasic catalytic generation of H 2 O 2 with Cu(II) protonated linear polymer and Fc or TTF has to be noted. [119] As nonmetalated porphyrins are protonated at liquid j liquid interface [120] they also catalyze biphasic ORR. [29,[121][122][123] When nonmetalated tetraphenylporphyrin is employed as a catalyst, stronger electron donor -DMFc is required for ORR at DCE j H 2 O.…”

“…Other macrocyclic mono‐, [115,116] bi‐, [117] and tetranuclear [118] Co(III) complexes with Schiff base ligands were employed as catalyst for biphasic ORR at DCE|H 2 O with Fc as electron donor. Biphasic catalytic generation of H 2 O 2 with Cu(II) protonated linear polymer and Fc or TTF has to be noted [119] …”