Bifunctional Platinum-Free Mixed Metal Oxygen Electrocatalysts Based on Naturally Abundant Peat

Several mixed metal oxygen electrocatalysts based on combinations of Fe, Co, and Ni were synthesized from naturally abundant well-decomposed peat. The desired composition of the materials was confirmed with SEM-EDS and the formed alloys were identified by XRD. The materials were then studied as catalysts for the oxygen reduction and evolution reactions in alkaline media using the rotating disc electrode method. It was observed that the catalysts formed an array of FeCo/PDC > FeNi/PDC > FeCoNi/PDC according to their oxygen reduction onset potential values. High oxygen evolution activity comparable to IrO2 was exhibited by the materials. Consequently, excellent bifunctional activity comparable to data from the literature was reached with all three synthesized catalysts. The best bifunctional activity was achieved with a catalyst based on Fe and Co which was evident in a low ΔE value of 0.75 V.