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Lookup NU author(s): Dr Ravikumar Ravikumar, Emeritus Professor Keith Scott, Professor Mohamed MamloukORCiD
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND).
Diethylmethylammonium trifluoromethanesulfonate [Dema][TfO], a protic ionic liquid, was used as an electrolyte for an intermediate temperature water electrolyser. In this study we fabricated polymer electrolyte membrane based on PTFE pore filled membrane impregnated with [Dema][TfO]. The activation energy obtained for an ionic conductivity was 8.12 kJ mol-1. Hydrogen evolution reaction (HER) and oxygen evolution reactions (OER) were studied in the solid-state cell with an in-situ RHE reference electrode, using Pt/C cathode and IrO2 anode respectively. The HER was observed at two different potentials, one at a peak potential of -0.47 V vs RHE with a limiting current density of -9.7 mA/cm2, assigned to reduction of hydronium ion. The second HER was observed at -0.63 V vs. RHE, assigned to the [Dema-H]+ cation reduction. Similarly, two oxidation peaks were assigned to OER one at 1.47 V and the second at 1.72 V vs RHE. The full cell water electrolyser achieved a current density of 70 mA/cm2 at 2.2 V with 50% RH at 100 oC. The stability of [Dema-H]+[TfO]- was studied with in-situ mass spectrometry which showed the loss of DEMA at > -0.8 V vs RHE while [TfO]- anion was stable up to 2.5 V vs RHE.
Author(s): Thimmappa R, Scott K, Mamlouk M
Publication type: Article
Publication status: Published
Journal: International Journal of Hydrogen Energy
Year: 2020
Volume: 45
Issue: 53
Pages: 28303-28312
Print publication date: 30/10/2020
Online publication date: 21/08/2020
Acceptance date: 02/08/2020
Date deposited: 07/08/2020
ISSN (print): 0360-3199
Publisher: Elsevier BV
URL: https://doi.org/10.1016/j.ijhydene.2020.08.016
DOI: 10.1016/j.ijhydene.2020.08.016
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