(560cu) Ternary and Quaternary Microwave Synthesized Electrocatalyst for Ethanol Oxidation

Shelby L. Foster¹, Patricia Means¹, Reid Eakin¹, Francis Osonga¹, and Lauren F. Greenlee¹

¹Department of Chemical Engineering, University of Arkansas, Fayetteville, Arkansas

The development of an electrocatalyst for the oxidation of the carbon-carbon (C-C) bond in long chain hydrocarbons would result in a liquid fuel flexible fuel cell. Ethanol is a common hydrocarbon used to investigate the oxidation of the C-C bond. Electrochemical studies show there are two pathways of electrooxidation of ethanol: 1) cleavage of the C-C bond which releases the maximum possible energy from the reaction, and 2) removal of two hydrogen atoms resulting in limited energy generation and overall poisoning of complete electrooxidation to carbon dioxide (CO₂). Several key metallic catalysts surfaces have been investigated to suppress the second pathway of electrooxidation of ethanol. Specifically, PtRhNi ternary nanoparticle catalyst have been shown to convert ethanol to CO₂ effectively with increased reactivity in alkaline environments. The increased reactivity of PtRhNi ternary nanoparticles in alkaline environments for electrooxidation of ethanol is the investigation of the project. Prior to the work by Boettcher and co-authors¹, Ni was believed to be the active site for water oxidation by Ni(OH)₂ catalysts in alkaline media. The identification of Fe doping into Ni(OH)₂ by electrolyte Fe impurities lead to Fe now attributed as being the active site for water oxidation. Therefore, PtRhNi ternary nanoparticles with Fe doping in alkaline environments will be investigated for electrooxication of ethanol reactivity.

The microwave synthesized PtRhNi ternary nanoparticles reactivity have been investigated in electrolyte free of Fe impurities and electrolyte containing Fe impurities. The electrolyte containing Fe impurities has resulted in higher current densities, indicating the Fe does in fact play a role in the electrooxidation of ethanol. In this presentation, I will present our work on ternary (PtRhNi) and quarternary (PtRhNiFe) nanoparticles for the electrooxidation of ethanol. The composition, morphology, surface characteristics, and electrochemical reactivity of the PtRhNi ternary nanoparticles and the PtRhNiFe quaternary nanoparticles will be discussed.

1. Trotochaud, L.; Young, S. L.; Ranney, J. K.; Boettcher, S. W., Nickel-iron oxyhydroxide oxygen-evolution electrocatalysts: the role of intentional and incidental iron incorporation. J Am Chem Soc 2014, 136 (18), 6744-53.