Solar Thermal Decoupled Electrolysis: Reaction Mechanism of Electrochemical Oxidation of CoO/Co(OH)2

Date of Award

Spring 2016

Project Type

Departmental Honors Paper/Project


Department of Chemistry

First Advisor

Jonathan Schoer


A modified water electrolysis process has been developed to produce H2. The electrolysis cell oxidizes CoO to CoOOH and Co3O4 at the anode to decrease the amount of electric work needed to reduce water to H2. The reaction mechanism through which CoO becomes oxidized was investigated, and it was observed that the electron transfer occurred through both a species present in solution and a species adsorbed to the electrode surface. A preliminary mathematical model was established based only on the electron transfer to species in solution, and several kinetic parameters of the reaction were calculated. The average value of each parameter over six data points was as follows: the diffusion coefficient of the reduced species (DR) was 1.03x10-3 cm2/s, the electron transfer coefficient (α) was 0.49, the standard rate constant (ko) was 6.87x10-6 cm/s, and reaction formal potential(Eof) was -0.284 V vs. Ag/AgCl. Based on poor results from curve fitting of experimental data obtained from chronoamperometry and cyclic voltammetry, it can be concluded that this model does not comprise the electrochemical system completely. Thus, the model should be updated to include the adsorbed species in the electron transfer step.