Hydrogen production through the electrolysis of water continues to be a key next-generation energy conversion and storage strategy with advantages including minimal greenhouse gas emissions, the lack of fossil fuels, and the potential as an alternative fuel source for fuel cells and reactant for industries such as ammonia production. Recent work by the Boettcher research group and others has demonstrated that iron incorporation into nickel hydroxide based catalysts can significantly enhance the activity of the catalyst for the oxygen evolution reaction (OER), which is the half reaction of water electrolysis known to limit the overall process with high overpotential and slow kinetics. With these recent developments in understanding the role of iron incorporation into nickel hydroxide and the importance of iron as the catalytic site for OER within these bimetallic electrocatalysts, there is now an opportunity to further develop nanostructured bimetallic iron-nickel hydroxide catalysts for improved OER performance in an alkaline electrochemical environment.<br/><br/>In this presentation, our results on the synthesis, characterization, and electrochemical testing of an iron-nickel hydroxide nanoparticle catalyst suite will be presented. Our ongoing work to develop and characterize a suite of bimetallic iron-nickel alloy hydroxide nanoparticle catalysts for the oxygen evolution reaction will be discussed. In particular, results will be presented for three iron-nickel compositions (1:5, 1:1, and 5:1 mol:mol Fe:Ni) and trends in both overpotential and stability will be discussed. Nanoparticle characterization via high resolution transmission electron microscopy, elemental analysis, and synchrotron-based x-ray absorption spectroscopy will be presented and discussed as a function of bimetallic composition. The role of nanoparticle structure in controlling activity and stability will be discussed, and electrochemical performance data will be used to demonstrate that both activity (i.e., overpotential) and stability (i.e., degradation rate as mV/hr) are critical to evaluate as we develop these catalysts for water splitting.

Understanding the structure of Fe-Ni hydroxide nanoparticle electrocatalysts

256th National Meeting (2018)

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