Synthesis of bimetallic iron-nickel nanoparticles for oxygen evolution and methanol oxidation catalysis under alkaline conditions for fuel cells

The electrochemical oxidation of alternative fuels, such as methanol and ethanol, for alkaline fuel cells often relies on the use of precious metal catalysts. However, the scarcity and high cost of these Pt group metals (Pt, Pd, Au, etc.) leads to the search for earth-abundant alternatives with similar electrocatalytic properties. Among these, iron emerges as a promising candidate as it has already been shown to have high activity for a variety of reactions. However, the rapid uncontrolled formation of oxides severely limits the stability of the iron nanoparticles. The addition of a second metal, such as nickel, slows this oxidation and can also enhance catalytic activity of the nanoparticles. In this work, bimetallic iron-nickel nanoparticles are synthesized using a multi-step procedure in water under ambient conditions. The electrochemical behavior can be tuned through slight changes during synthesis, leading to catalytic nanoparticles that show enhanced activity for either the oxygen evolution reaction (OER) or methanol oxidation under alkaline conditions. Possible explanations for these differences in catalytic activity are explored through several characterization methods and show the level of structural disorder and the formation of various iron and nickel oxides during synthesis likely contribute to the altered behavior. Future plans for the project will also be discussed.