Title : “Hydrogen Evolution Reaction on polycrystalline Au electrode in acidic and alkaline media using Inverted rotating disc electrode.”
Biography of the Speaker :
Ph.D Scholar in the Dept. of Chemical Engg. (QIP)
Affiliation of the Speaker :
Prof. S. Ramanathan – Guide
Abstract :
The mechanism of hydrogen evolution reaction (HER) on Au in perchloric acid and NaOH soluti ons was studies using an inverted rotating disc electrode (IRDE). IRDE enables investigations of gas evolution reactions in a large potential and current window, as the electrode surface is not blocked by gas bubbles in this configuration. Potentiodynamic polarization data were acquired at various concentration of HClO4 and NaOH and at different electrode rotational speeds. At large over-potentials, diffusion-limited currents were observed in HClO4 solutions.The effect of bubbles on electrode surface area and variation in boundary layer thickness was incorporated into the models for HER. VHT model best describes the polarization results for HER on Au in acidic media. The model predicted fractional surface coverage of adsorbed hydrogen, rate of reaction for individual steps, boundary layer thickness, and bubble coverage as a function of potential were also estimated. In the alkaline media, HER rate was found to be independent of NaOH concentration and electrode rotational speed, and t he reaction mechanism could not be identified unambiguously