Investigation of NiFe-Based Catalysts for Oxygen Evolution in Anion-Exchange Membrane Electrolysis

Sabrina Campagna Zignani,Sabrina Campagna Zignani,Stefano Trocino,Stefano Trocino,Antonino Salvatore Aricò,Massimiliano Lo Faro,Massimiliano Lo Faro

doi:10.3390/en13071720

Sabrina Campagna Zignani, Sabrina Campagna Zignani + Show 5 more

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https://doi.org/10.3390/en13071720

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Abstract

NiFe electrodes are developed for the oxygen evolution reaction (OER) in an alkaline electrolyser based on an anion exchange membrane (AEM) separator and fed with diluted KOH solution as supporting electrolyte. This study reports on the electrochemical behaviour of two different NiFe-oxide compositions (i.e., Ni1Fe1-oxide and Ni1Fe2-oxide) prepared by the oxalate method. These catalysts are assessed for single-cell operation in an MEA including a Sustainion™ anion-exchange membrane. The electrochemical polarization shows a current density of 650 mA cm−2 at 2 V and 50 °C for the Ni1Fe1 anode composition. A durability test of 500 h is carried out using potential cycling as an accelerated stress-test. This shows a decrease in current density of 150 mA cm−2 mainly during the first 400 h. The performance achieved for the anion-exchange membrane electrolyser single-cell based on the NiFeOx catalyst appears promising. However, further improvements are required to enhance the stability under these operating conditions.

Highlights

The role of H2 as an energy vector is becoming progressively a solid choice [1]
Alkaline solid membrane-based electrolysers represent an oxygen evolution reaction (OER) reaction, further enhancements are still necessary in terms of composition, stability and facile interesting technology
A simple reaction, further enhancements are still necessary in terms of composition, stability and facile method for the synthesis of two compositions of NiFe based materials (i.e., Ni:Fe = 1:1 and 1:2) was synthesis methods for their preparation and utilisation in practical devices

Summary

Introduction

The role of H2 as an energy vector is becoming progressively a solid choice [1]. various processes to produce pure H2 are available (i.e., catalytic-, thermal- and electrochemical-based routes) [2,3,4,5], research is looking at how to improve the efficiency and reliability of these technologies.Electrolysis of liquid water is one of the most used technologies to produce pure and green H2 , but several issues regarding to the use of a highly concentrate caustic solution (7 M KOH) as liquid electrolyte have hindered its wide use. Liquid alkaline electrolyte based electrolysers, using concentrated solution of KOH or NaOH [6,7,8,9,10], have shown significant corrosion effects on the hardware. These drawbacks have affected the wide use of this technology. A solution to the issues caused by the use of concentrated liquid electrolytes is to develop alkaline electrolysers based on a solid polymer electrolyte separator with a zero gap configuration (membrane-electrode assembly) requiring less concentrated KOH solution [12]

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