Synthesis of PtCu/C Nanostructured Electrocatalysts for the Oxygen Reduction Reaction via One-Step Electrochemical Erosion

TL;DR

Scientists created a new type of electrocatalyst using platinum and copper that is more efficient and easier to produce for fuel cells.

Contribution

A one-step, surfactant-free method to synthesize PtCu nanoparticles with high ORR mass activity is introduced.

Findings

PtCu/C catalysts achieved mass activities of ∼1.2 A mgPt–1 at 0.9 V.

The method avoids surfactants and capping agents, simplifying production.

PtCu nanoparticles outperform state-of-the-art Pt-based catalysts.

Abstract

Reducing the precious metal loading while increasing
the oxygen
reduction reaction (ORR) mass activity of novel electrocatalysts constitutes
one of the remaining key challenges in the widespread application
of proton exchange membrane fuel cells, which is inevitable for the
transition to the climate-neutral hydrogen economy. However, this
requires a simple, scalable, and affordable production of active nanostructured
electrocatalysts. Alloyed nanoparticles of Platinum (Pt) with transition
metals like cobalt, nickel, or copper have shown promising activity
toward ORR, but their preparation usually involves complex multistep
processes and environmentally harmful surfactants or structure-capping
agents. In this work, we present the successful synthesis of nonspherical
copper-alloyed Pt nanoparticles (PtCu) by employing a simple one-step
top-down approach without surfactants or capping agents. The electrocatalysts
were characterized by high-resolution transmission electron microscopy,
energy-dispersive X-ray spectroscopy, X-ray diffraction, X-ray photoelectron
spectroscopy, and inductively coupled plasma mass spectrometry. The
ORR kinetics were evaluated using the rotating (ring) disk electrode
technique. The synthesized PtCu/C catalysts revealed outstanding mass
activities of ∼1.2 A mgPt
–1 at
0.9 V vs the reversible hydrogen electrode, which clearly surpasses
state-of-the-art Pt-based catalysts in the literature and demonstrates
the highest ORR mass activities reported for PtCu nanoparticles.

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