Er-Modulated NiFe Layered Double Hydroxides for Durable High-Current-Density Seawater Oxidation

Area of Science:

• Electrochemistry
• Materials Science
• Sustainable Energy

Background:

• Direct seawater electrolysis is a promising green hydrogen production method.
• Durable anode catalysts are essential for practical seawater electrolysis due to corrosive chloride-rich conditions.

Purpose of the Study:

• To develop a robust oxygen-evolution anode catalyst for efficient and stable seawater oxidation.
• To investigate the role of Erbium (Er) incorporation in enhancing catalyst durability and performance.

Main Methods:

• Synthesis of Erbium-incorporated Nickel Iron layered double hydroxide on nickel foam (Er-NiFe LDH/NF).
• Electrochemical characterization of the catalyst's performance in seawater electrolysis.
• Long-term stability testing of the catalyst and an assembled electrolyzer.

Main Results:

• The optimized Er-NiFe LDH/NF catalyst demonstrated a low overpotential of 350 mV at 1000 mA cm-2.
• The catalyst maintained high current density for 1000 hours, showing excellent durability.
• An anion exchange membrane electrolyzer with Er-NiFe LDH/NF achieved 500 mA cm-2 at 2.20 V for 500 hours.

Conclusions:

• Erbium incorporation effectively suppresses chloride-induced corrosion and enhances catalyst performance.
• Er-NiFe LDH/NF is a highly robust and efficient anode for direct seawater electrolysis.
• This advancement supports the large-scale production of green hydrogen via sustainable methods.