The Performance of Nickel and Nickel-Iron Catalysts Evaluated As Anodes in Anion Exchange Membrane Water Electrolysis

Abstract

Anion exchange membrane water electrolysis (AEMWE) is an efficient, cost-effective solution to renewable energy storage. The process includes oxygen and hydrogen evolution reactions (OER and HER); the OER is kinetically unfavourable. Studies have shown that nickel (Ni)- iron (Fe) catalysts enhance activity towards OER, and cerium oxide (CeO2) supports have shown positive effects on catalytic performance. This study covers the preliminary evaluation of Ni, Ni90Fe10 (at%) and Ni90Fe10/CeO2 (50 wt%) nanoparticles (NPs), synthesized by chemical reduction, as OER catalysts in AEMWE using commercial membranes. Transmission electron microscopy (TEM) images of the Ni-based NPs indicate NPs roughly 4–6 nm in size. Three-electrode cell measurements indicate that Ni90Fe10 is the most active non-noble metal catalyst in 1 and 0.1 M KOH. AEMWE measurements of the anodes show cells achieving overall cell voltages between 1.85 and 1.90 V at 2 A cm−2 in 1 M KOH at 50 °C, which is comparable to the selected iridium-black reference catalyst. In 0.1 M KOH, the AEMWE cell containing Ni90Fe10 attained the lowest voltage of 1.99 V at 2 A cm−2. Electrochemical impedance spectroscopy (EIS) of the AEMWE cells using Ni90Fe10/CeO2 showed a higher ohmic resistance than all catalysts, indicating the need for support optimization.

Recent Advances of CeO2‐Based Electrocatalysts for Oxygen and Hydrogen Evolution as well as Nitrogen Reduction

“…In another work, the chemical reduction synthesized Ni 90 Fe 10 /CeO 2 needs an overpotential of 369 mV at 10 mA • cm À 2 current density. [48] These rich research fruits have opened new avenue to develop efficient CeO 2 /metal hybrid catalysts for OER, ORR, HER, and even other possible electrochemical processes.…”

“…The Fe x Ni y /CeO 2 /NC is also a bifunctional electrocatalyst, achieving hydrogen evolution and water splitting with a 1.70 V cell voltage to drive 10 mA ⋅ cm −2 current. In another work, the chemical reduction synthesized Ni 90 Fe 10 /CeO 2 needs an overpotential of 369 mV at 10 mA ⋅ cm −2 current density [48] . These rich research fruits have opened new avenue to develop efficient CeO 2 /metal hybrid catalysts for OER, ORR, HER, and even other possible electrochemical processes.…”

Durability of a recombination catalyst-based membrane-electrode assembly for electrolysis operation at high current density

“…However, some issues need to be overcome for a large-scale deployment of this technology. Safety issues, related to the operation at high differential pressures, and cost of electrolysis systems are among the main drawbacks [4,18,19,23,25,[28][29][30][31][32].…”

A Review on Ceo2‐Based Electrocatalyst and Photocatalyst in Energy Conversion

“…[ 48 ] The bimetal alloy and hydroxide were also composited with CeO 2 to enhance the OER activity. [ 49–53 ] Chen et al constructed Fe x Ni y /CeO 2 /NC catalyst and attributed its enhanced OER activity to the high oxygen‐storage capacity of CeO 2 , which enabled the immediate adsorption of the generated O 2 during OER process. [ 51 ] Transition metal oxide was considered as an important type of OER catalyst due to the remarkable redox capability and mixed valences.…”