Bimetallic nanoparticles of Pt and Pd often show higher activity for formic acid electrooxidation (FAEO) when compared to their monometallic counterparts. The mechanism behind this improvement is still debated as many factors can influence the surface-adsorbate interactions at a metal surface and include particle size, shape, composition, and architecture (<i>e.g., </i>hollow or core@shell). Here, size- and shape-controlled core@shell nanoparticles are studied as catalysts for FAEO in order to systematically examine the contribution of lattice strain on catalyst performance. Specifically, {100}-terminated Pd@Pt, Pt@Pd, Pd, and Pt nanocubes were synthesized and their electronic and catalytic properties were compared. The nanocube shape was selected as both Pd(100) and Pt(100) show the highest activity for FAEO when compared to other low index Pd and Pt surfaces, respectively. The Pd@Pt and Pt@Pd architectures were prepared by seeded methods and selected to compare systems where the shell metal is compressed <i>versus</i> in tension. This difference arises due to the lattice mismatch between the core and shell metals. The monometallic counterparts, Pd and Pt, serve as references to these strained systems, with all samples being characterized by advanced electron microscopy, electrochemical methods, and X-ray photoelectron spectroscopy. Through this research, nanoparticle architecture is shown to be an effective lever to systematically control surface strain in bimetallic systems. As FAEO is a model for other organic fuel systems, this study should more broadly accelerate catalyst design.

Systematic examination of bimetallic architecture in Pt-Pd nanocatalysts

253rd National Meeting (2017)

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