High‐Efficiency Anion‐Exchange Membrane Water Electrolyzer Enabled by Ternary Layered Double Hydroxide Anode

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 17; no. 28; pp. e2100639 - n/a
• Main Authors: Lee, Jooyoung, Jung, Hyeonjung, Park, Yoo Sei, Woo, Seongwon, Yang, Juchan, Jang, Myeong Je, Jeong, Jaehoon, Kwon, Nayoung, Lim, Byungkwon, Han, Jeong Woo, Choi, Sung Mook
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.07.2021
• Subjects: anion exchange membrane water electrolyzers; Anion exchanging; Catalysts; Current density; Density functional theory; electrocatalysts; Electrodes; Electrolysis; Hydroxides; Membranes; Metal foams; Nanotechnology; oxygen evolution reaction; Oxygen evolution reactions; Platinum; transition metals
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.202100639

Developing high‐efficiency and low‐cost oxygen‐evolving electrodes in anion exchange membrane (AEM) water electrolysis technology is one of the major challenges. Herein, it is demonstrated that the surface corrosion of a conventional Ni foam electrode in the presence of Fe3+ and V3+ cations can transform it into an electrode with a high catalytic performance for oxygen evolution reaction (OER). The corroded electrode consists of a ternary NiFeV layered double hydroxide (LDH) nanosheet array supported on the Ni foam surface. This NiFeV LDH electrode achieves an OER current density of 100 mA cm−2 at an overpotential of 272 mV in 1 m KOH, outperforming the IrO2 catalyst by 180 mV. Density functional theory calculations reveal that the unique structure and the presence of vanadium in NiFeV LDH play a key role in achieving improved OER activity. When coupled with a commercial Pt/C cathode catalyst, the resulting AEM water electrolyzer achieves a cell current density as high as 2.1 A cm−2 at a voltage of only 1.8 Vcell in 1 m KOH, which is similar to the performance of the proton exchange membrane water electrolyzer obtained from the IrO2 and Pt/C catalysts pair. The anion exchange membrane (AEM) water electrolysis remains in the research stage despite the advantage of being able to use non‐precious metals because of its lower performance than the proton exchange membrane (PEM) water electrolyzer. In this study, the developed ternary NiFeV layered double hydroxide electrode is to provide a reasonably designed method for AEM water electrolysis performance similar to PEM water electrolyzer.