Highly Catalytic Amorphous Ni–P Synthesized via Pulsed Electrodeposition

Ni–P coatings have attracted wide attention due to their good tribological properties, corrosion resistance, and high catalytic activity. The surface properties impact the overall catalytic performance of Ni–P as electrocatalysts. In this study, highly catalytic amorphous Ni–P electrodeposits are synthesized using pulsed electrodeposition technique. Pulse parameters show a significant effect on the morphology, crystallinity, and electro‐catalytic activity of the deposits. The Ni–P deposits are found to be amorphous up to the duty cycle of 50%, whereas higher duty cycles (toward direct current deposition) result in a transition to nanocrystalline structure. This is attributed to an indirect reduction process involving intermediate phosphine leading to co‐deposition of phosphorus and nickel. Change in pulse frequency results in significant variations in surface morphology. Methanol electro‐oxidation in alkaline environment is studied as a function of surface morphology for the amorphous Ni–P catalysts. Up to four‐fold increase in oxidation peak current is observed for nano‐morphologies with large electrochemical surface area synthesized at pulse frequency of 50 Hz. This demonstrates the potential of pulsed electrodeposition as a versatile toolbox for obtaining highly catalytic amorphous Ni–P as a potential substitute for expensive noble‐metals used in direct alcohol fuel cells.