Pt-Ni nanoparticles were vastly explored because of the synthetic tunability and the high electrochemical performance toward oxygen reduction reaction (ORR), the application and high-efficiency catalytic activity are commonly confined for acidic medium due to the Pt corrosion in alkaline medium. The alternative Ni-rich nanoparticles investigated as oxygen evolution reaction (OER) catalyst have shown insufficient efficiency in the acidic medium because of the known transition metal leaching process. The novelty in our work is the ability to produce an active bifunctional catalyst that accomplishes both ORR and OER in alkaline medium. Our advance was accomplished by a comprehensive investigation of the synthesis parameters and by a rational material design. The ultralow-platinum Pt@Ni@Pt core-bishell nanorods achieve an unprecedented (for a Pt-based catalyst) overpotential of 0.29 V at 10 mA cm-2 and current density of 162 mA µg-1Pt at 1.6 V (vs. RHE) for the OER, while still maintaining a very decent value of 0.32 A mg-1Pt at 0.85 V for the ORR. These values outperform the standard Pt catalyst for the ORR and the Ni catalyst for the OER, using less than 1%wt. Pt. This work advances the field of ultra-low platinum content, which in our point of view will be one of the critical issues that will allow the green energy technology to be implemented. Also, this research revealed a unique methodology that allows morphology and size tunability of Pt@Ni core-shell nanoparticles. The kinetic control of the core and the shell was achieved by combining two commonly used solvents as reducing agents while keeping the (111) plane electrochemically active. We highlight that the understanding of the relationships between the composition of a material and its structure and properties is a fundamental objective and a key challenge in nanoscience research.

Ultralow-platinum Pt@Ni@Pt Core-bishell nanorods bifunctional oxygen evolution and reduction electrocatalyst in alkaline medium

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.