Type

Journal Article

Authors

Ce Zhang
Francis Verpoort
Kari Laasonen
Nazir Ahmad
Matthias Vandichel
Yan Zhang
Hussein A. Younus
Shiguo Zhang

Subjects

Chemistry

Topics
cu metal organic material electrochemical water oxidation highly active neutral conditions molecular catalyst cm 1 oxygen evolution dft calculations

Highly active copper‐based electrocatalyst for water oxidation at neutral pH (2020)

Abstract The full text of this article will not be available in ULIR until the embargo expires on the 15/07/2021 The sluggish kinetics of the oxygen evolution reaction at the anode severely limits the hydrogen production at the cathode in water spitting systems. While electrocatalytic systems based on cheap and earth-abundant metal copper catalysts have been promising for water oxidation under basic conditions, only very few examples with high overpotential can be operated under acidic or neutral conditions, even though hydrogen evolution in the latter case is much easier. This work presents an efficient and robust Cu-based molecular catalyst, which self-assembles as a periodic film from its precursors under aqueous conditions on the surface of glassy carbon electrodes (GCE). This film catalyzes the oxygen evolution reaction (OER) under neutral conditions with impressively low overpotential. In controlled potential electrolysis, a stable catalytic current of 1.0 mA/cm2 can be achieved at only 2.0 V (vs. RHE) and no remarkable decrease in the catalytic current is observed even after prolonged bulk electrolysis. The catalyst displays first-order kinetics and a single site mechanism for water oxidation with a TOF (kcat) of 0.6 s-1. DFT calculations are performed to study the OER behavior of the periodic Cu(TCA)2 (HTCA = 1-mesityl-1H-1,2,3-triazole-4 carboxylic acid) film and reveal that TCA defects within the film create Cu(I) active sites which can provide a low overpotential route for OER. This route involves Cu(I), Cu(II)-OH, Cu(III)=O and Cu(II)-OOH intermediates and is enabled at a potential of 1.54 V (vs. RHE), requiring an overpotential of 0.31 V. This corresponds well with an overpotential of ~ 0.29 V obtained experimentally for the grown catalytic film after 100 CV cycles at pH=6. However, to reach a higher current density of 1 mA cm−2, an overpotential of 0.72 V is required.
Collections Ireland -> University of Limerick -> Centres Science and Engineering
Ireland -> University of Limerick -> Faculty of Science and Engineering
Ireland -> University of Limerick -> Bernal Institute

Full list of authors on original publication

Ce Zhang, Francis Verpoort, Kari Laasonen, Nazir Ahmad, Matthias Vandichel, Yan Zhang, Hussein A. Younus, Shiguo Zhang

Experts in our system

1
Matthias Vandichel
University of Limerick
Total Publications: 4
 
2
Yan Zhang
University College Cork
Total Publications: 7