ABSTRACT The distribution of metals in alloy nanoparticles is a key parameter in their electrochemical performance. Here, we show that for Pt–Au alloys this distribution dynamically responds to the electrochemical environment. Using electrochemical X‐ray photoelectron spectroscopy, we find that the surface composition of the alloy can range from stoichiometric to Pt‐enriched, depending on the applied potential. The driving factors for this restructuring are the differences in electronegativity and mobility between Pt and Au. At potentials below 1.5 VRHE, the slightly more reactive (less electronegative) Pt shows surface enrichment, which slowly increases as the potential is raised and increasingly oxidizing adsorbates are formed. Above 1.5 VRHE, oxidation of the more mobile Au atoms becomes possible, which is kinetically favored over Pt oxidation, thereby driving Au toward the surface. All surface dynamics are found to be highly reversible, even at room temperature. This facile rearrangement suggests that dynamic restructuring of alloy nanoparticles occurs in a wide range of conditions, and should therefore be taken into account in alloy electrocatalyst design.
Electrocatalytic ammonia oxidation reaction (EAOR) remains hindered by the lack of catalysts that simultaneously achieve high activity and long-term stability. Herein, we report a surface compositional gradient PtFe alloy catalyst (G-PtFe) consisting of a Pt-Fe gradient shell and a PtFe alloy core. The G-PtFe deliv...
Ru-Yan Wu, Yang Liu, Yong-Zhen Jin et al.· Nano Reseach· 0 citations
Due to their unique properties, bimetallic platinum-based alloys often exhibit superior activity compared to their parent counterparts for many catalytic reactions. Nevertheless, as multimetallic systems, they often undergo compositional and structural changes under reactive conditions, potentially compromising perform...
J. Kučera, Athira Lekshmi Mohandas Sandhya, M. Vorochta et al.· ACS Applied Materials and In...· 0 citations
Surface metal-organic frameworks (SMOFs) are promising platforms for catalysis, yet their structural response to electrochemical bias is often overlooked. We report the potential-driven activation of an N-heterocyclic carbene (NHC)-based SMOF on Au(111) for the hydrogen evolution reaction (HER). Operando electrochemica...
Surface–subsurface partitioning of alloying elements affects stability, strain, and adsorption energetics in heterogeneous catalysis yet remains difficult to control. Here, we use first-principles calculations and atomistic modeling to show that AuM binary alloys (M = Cu, Pd) provide a model platform for understandin...
Mailde S. Ozório, Jan Rossmeisl· ACS Catalysis· 0 citations
Real‐time monitoring of structural evolution and identification of intrinsic active sites during electrocatalysis are vital to the rational design of high‐performance electrocatalysts. Herein, PtCu bimetallic alloy electrocatalyst is synthesized for the electrochemical 5‐hydroxymethylfurfural oxidation reaction (HMFO...
Hao-Jing Hu, Fen Wang, Zhi-Jie Kong et al.· Advanced Functional Material...· 0 citations
Electrocatalytic nitrogen reduction is a vital strategy for green ammonia production. However, this is highly challenged by poor selectivity, and hence, the development of novel catalysts is scanty. The present research provides insight into the development of a new trimetallic alloy, CuAgMo, on multiwalled carbon na...
Muzammil Hussain, K. B. Ibrahim, T. Shifa et al.· ChemElectroChem· 0 citations
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