In a quest to combat the challenges associated with global warming, several renewable sources of energy are currently being explored as alternatives to fossil fuel energy sources. One of those promising alternatives is the hydrogen fuel cell (HFC) which can produce energy liberating water as its major waste product. To reduce the costs associated with the design and fabrication of the cathode material in these cells, we are currently studying the oxygen reduction reaction (ORR) using first-row transition metals, which are more abundant and much less expensive than the platinum normally used for this application. Although iron, manganese, and cobalt complexes with a variety of ligand scaffolds have been able to electrocatalytically reduce molecular oxygen, few of these contain electron-proton transfer mediating groups that may improve both the efficiency and selectivity of the catalyst for the ORR. Here, we report a stable pentadentate (N4O) iron(II) complex bearing a pendent quinol group. This first-row transition metal complex was synthesized and extensively characterized using H-NMR, mass spectrometry, UV-visible spectroscopy, and elemental analysis. The compound is an effective electrocatalyst, capable of achieving complete oxygen reduction at a turnover frequency (TOF) of 95600 s<sup>-1</sup> and an effective overpotential of (0.360 V) as determined using cyclic voltammetry (CV). This catalyst also has about 100% selectivity for water as determined using the TiOSO<sub>4</sub> assay.

Fe(II) complex with a redox-active organic ligand acts as an electrocatalyst for the reduction of dioxygen

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