Electrodeposited Pt on NiFe layered double hydroxide/Ni foam electrode for an extremely active and durable electrocatalyst for ammonia oxidation reaction

Abstract

With the increasing demand for clean energy to achieve a carbon-neutral society, ammonia (NH3) has emerged as a hydrogen carrier due to its high hydrogen energy density, low volatility, and its ability for long-term storage and transport. Ammonia electrolysis is a promising hydrogen generation technology because it requires low theoretical voltage (0.06V) and mild operating conditions, such as relatively low temperatures and pressures. Platinum (Pt) is a selective and active electrocatalyst for ammonia oxidation to nitrogen, with the lowest overpotential among single-metal catalysts. However, the poisoning effect that blocks the catalytic active sites limits its long-term catalytic performance. In this work, we report a Pt-deposited NiFe layered double hydroxide (LDH) electrocatalyst prepared on Ni foam that achieves high hydrogen production efficiency through its large specific surface area. Notably, we address the way of mitigating the poisoning of Pt/NiFe LDH catalysts using a pulse-cycling method applicable across various electrolyte conditions. This approach facilitates the desorption of adsorbed nitrogen intermediates responsible for poisoning, achieving 150h of operation without significant performance degradation − the longest stability reported for an ammonia oxidation electrocatalyst to date. This work presents a novel catalytic technology for long-term stable hydrogen production through ammonia electrolysis with low power consumption, representing a significant step toward advancing the commercial viability of hydrogen production through ammonia electrolysis.

Files

Additional details