Selective deposition of Pt onto supported metal clusters for fuel cell electrocatalysts

Abstract

We report a new method for deposition of Pt on a metal core to develop real electrocatalysts with significantly reduced amounts of expensive Pt as well as enhanced activity for oxygen reduction reaction. Ru and Pd have different crystal structures and modify the electronic structure of Pt to a different extent (shifts in d-band center). They were chosen as core materials to examine whether hydroquinone dissolved in ethanol can be used to deposit additional Pt atoms onto preformed core nanoparticles, and whether the modified d-character of Pt on different host metals can result in the enhanced ORR activity. The physicochemical characteristics of Pd-Pt and Ru-Pt core-shell nanoparticles are investigated. The core-shell structure was identified through a combination of experimental methods, employing electron microscopy, electrochemical measurements, and synchrotron X-ray measurements such as powder X-ray diffraction, X-ray absorption fine structure, and X-ray photoelectron spectroscopy. The hydroquinone reduction method proved to be an excellent route for the epitaxial growth of a Pt shell on the metal cores, leading to enhanced ORR activities.

Porous Hollow‐Structured LaNiO3 Stabilized N,S‐Codoped Graphene as an Active Electrocatalyst for Oxygen Reduction Reaction

“…For that reason, the energy conversion of these devices is normally less than 70% . Well‐dispersed Pt and Pt‐alloy nanostructures on carbon based materials have been the most widespread commercialized catalysts to improve ORR efficiency, due to their excellent electronic conductivity, superior catalytic performance, and high chemical stability . But the high cost, easy CO poisoning, coarsening possibility, and ready defeat from the cathode lead to decrease in the electrochemical surface area of Pt, and hence its catalytic activity .…”

Climbing the Activity Volcano: Core–Shell Ru@Pt Electrocatalysts for Oxygen Reduction

“…It has been demonstrated that Ru@Pt exhibits enhanced performance for methanol oxidation and CO‐tolerant hydrogen oxidation and it has been suggested that this enhancement is due to weakening of CO binding 13–17. However, there are only a few investigations of these electrocatalysts for oxygen reduction and they show little or no catalytic improvement 18–20. In a recent work, Adzic and co‐workers have synthesized Ru@Pt with varying shell thickness using a Cu underpotential deposition (UPD) deposition technique and report enhanced activity 21.…”

Realization of Both High-Performance and Enhanced Durability of Fuel Cells: Pt-Exoskeleton Structure Electrocatalysts

“…The half-cell activities of the Pd-Pt/C catalysts ( Figure S1) clearly demonstrated that the particles had good catalytic activity for ORR that was comparable to that of commercial Pt/C. 24 In addition, the Pd-Pt/C catalysts performed remarkably well in a practical PEMFC device: i.e., an MEA in a single cell ( Figure 2). Figure Cell performance was compared at 0.7 V because activation kinetics were dominant in the low current region (Figure 2b).…”

“…Results and Discussion 3.1 Single cell performance in the ADT Carbon-supported bimetallic catalysts were prepared using a hydroquinone reduction method, as described in our previous study. 24 The core base metal was Pd and the exoskeleton metal was Pt. The catalyst inks for the cathode were fabricated using the developed Pd-Pt/C catalysts, and a commercial Pt/C catalyst.…”