Multifold nanotwin-enhanced catalytic activity of Ni-Zn-Cu for hydrazine oxidation

Abstract

The hydrazine oxidation reaction (HzOR) plays a critical role in direct hydrazine fuel cells and presents a promising alternative to the kinetics-sluggish oxygen evolution reaction in water reduction. Engineering catalysts with high-density multifold nanotwin structures has emerged as a compelling strategy to enhance catalytic activity. However, the exploration of multifold nanotwins for HzOR applications remains absent. Herein, we report the successful synthesis of a porous Ni-Zn-Cu catalyst featuring high-density twofold and fivefold nanotwins. The Ni-Zn-Cu catalyst supported on Ni foam (Ni-Zn-Cu/Ni foam) exhibits exceptionally high catalytic activity and stability toward the HzOR, achieving a current density of 204.3 mA cm−2 at 0.0 V vs. RHE and retaining up to 89.1 % after 20 h of continuous electrolysis. Online mass spectrometer (MS) analysis indicates that the Ni-Zn-Cu coating facilitates NN bond cleavage of N2H4. This study offers valuable insights into the development of multifold nanotwin catalysts for advancing HzOR applications.