Bimetallic PtNi catalyst for electrochemical ammonia oxidation reaction

The development of highly active and alkaline-stable ammonia oxidation reaction (AOR) catalysts with exceptionally low onset potential and superior performance remains a significant scientific pursuit. This difficulty stems from the inherently slow kinetics of the AOR and the tendency of catalyst surfaces to undergo poisoning, which has been reported across nearly all known material systems. To accelerate the sluggish AOR kinetics, herein, we have grown PtNi nanoparticles on Ti Mesh via one-step electrodeposition method. The resulting PtNi catalyst demonstrates exceptional AOR activity and stability in alkaline media, achieving an ultralow onset overpotential potential of 0.41 V and a peak current density of 162.2 mA cm −2 . Furthermore, a 24 h pulse electrolysis study utilizing the PtNi catalyst achieved 96% ammonia removal, showcasing its exceptional efficiency in the AOR. Moreover, after 500 cyclic voltammetry durability testing, the peak current density exhibited only a 25.8% decline, indicating remarkable stability. This improved electrochemical performance is primarily due to the unique advantages of binder-free deposition, large electrochemical surface area, as well as strong ammonia adsorption, and efficient electron transfer capabilities of the PtNi nanoparticles. This study shows valuable insights into the rational design and synthesis of highly efficient bimetallic electrocatalysts, showcasing their potential for competitive performance in diverse ammonia electrolysis applications. • PtNi nanoparticles were successfully synthesized using an electrodeposition method. • The prepared PtNi nanoparticles exhibit enhanced ammonia oxidation reaction (AOR) activity. • The high peak current density of ∼162 mA cm −2 was achieved in 1 M KOH with 1 M NH 4 OH. • The enhanced electrochemical performance is attributed to synergy between Pt and Ni.