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1. Colloidal synthesis of monodisperse trimetallic Pt–Fe–Ni nanocrystals and their enhanced electrochemical performances

   https://doi.org/10.1088/1361-6528/aca337  

   Li, Can; Pan, Jinfong; Zhang, Lihua; Fang, Jiye (December 2022, Nanotechnology)

   Abstract Among the multi-metallic nanocatalysts, Pt-based alloy nanocrystals (NCs) have demonstrated promising performance in fuel cells and water electrolyzers. Herein, we demonstrate a facile colloidal synthesis of monodisperse trimetallic Pt–Fe–Ni alloy NCs through a co-reduction of metal precursors. The as-synthesized ternary NCs exhibit superior mass and specific activities toward oxygen reduction reaction (ORR), which are ∼2.8 and 5.6 times as high as those of the benchmark Pt/C catalyst, respectively. The ORR activity of the carbon-supported Pt–Fe–Ni nanocatalyst is persistently retained after the durability test. Owing to the incorporation of Fe and Ni atoms into the Pt lattice, the as-prepared trimetallic Pt-alloy electrocatalyst also manifestly enhances the electrochemical activity and durability toward the oxygen evolution reaction with a reduced overpotential when compared with that of the benchmark Pt/C (△ η = 0.20 V, at 10 mA cm −2 ). This synthetic strategy paves the way for improving the reactivity for a broad range of electrocatalytic applications. 

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2. Facet-dependent Catalysis of CuNi Nanocatalysts toward 4–Nitrophenol Reduction Reaction

   https://doi.org/10.1557/adv.2020.5  

   Li, Can; Luan, Yiliang; Zhao, Bo; Kumbhar, Amar; Chen, Xiaobo; Collins, David; Zhou, Guangwen; Fang, Jiye (January 2020, MRS Advances)

   ABSTRACT We report a facile method to fabricate CuNi nano-octahedra and nanocubes using a colloidal synthesis approach. The CuNi nanocrystals terminated with exclusive crystallographic facets were controlled and achieved by a group of synergetic capping ligands in a hot solution system. Specifically, the growth of {111}-bounded CuNi nano-octahedra is derived by a thermodynamic control, whereas the generation of {100}-terminated CuNi nanocubes is steered by a kinetic capping of chloride. Using a reduction of 4-nitrophenol with sodium borohydride as a model reaction, CuNi nano-octahedra and nanocubes demonstrated a strong facet-dependence due to their different surface energies although both exhibited remarkable catalytic activity with the high rate constant over mass (k/m). A kinetic study indicated that this is a pseudo first-order reaction with an excess of sodium borohydride. CuNi nanocubes as the catalysts showed better catalytic performance (k/m = 385 s -1 •g -1 ) than the CuNi nano-octahedra (k/m = 120 s -1 •g -1 ), indicating that 4-nitrophenol and hydrogen were adsorbed on the {100} facets with their molecules parallel to the surface much easier than those on {111} facets. 

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3. Strain in Core–Shell Spinel Nanocrystals Enhances ORR Activity

   https://doi.org/10.1021/acscatal.5c00896  

   Rowell, Jonathan L; Joshi, Aditya; Tan, Haotian; Yoon, Dasol; Manassa, Jason; Stangel, Alex; Bundschu, Colin; Jia, Yafu; Abruña, Héctor D; Hovden, Robert; et al (June 2025, ACS Catalysis)

   Strain engineering of electrocatalysts has been an extensively studied field in recent years, but there has been limited investigation of strain and ligand effects in the catalysts of heterostructured oxides. Such studies could have significant impacts as the localized changes in the electronic structure of metal oxide shells may induce enhanced catalytic activity, complementing those from the well-studied metallic systems. Here, we developed a colloidal synthesis route to monodisperse core–shell spinel oxide nanocrystals with tunable shell thickness for the oxygen reduction reaction (ORR) in alkaline media. We compare the activity of these heterostructured particles, finding a higher activity for smaller shell thicknesses. The smallest shell thickness aligns with the highest shell strain. The best-performing core–shell sample achieved a half-wave potential of 0.893 V versus RHE in 1.0 M KOH, making it one of the best-reported values for a spinel oxide electrocatalyst for alkaline ORR with a PGM-free catalyst. In addition, this value is within 11 mV of that of the Pt/C reference material. Though a Pt/C reference sample has an overall higher mass activity at 0.9 V vs RHE, when cost is considered, the strained spinel outperforms the Pt/C by over 600-fold at this potential. Our results provide an impetus for exploring the deliberate and controlled use of strain engineering in metal oxides as high-performance, low-cost electrocatalysts. 

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4. Layer-by-Layer Electrodeposition of Gold and Ruthenium Using Self-Assembly for Oxygen Reduction

   https://doi.org/10.1149/1945-7111/adfeec  

   Padovan, Quinn A; Bhoumik, Nikhil C; Barile, Christopher J (September 2025, Journal of The Electrochemical Society)

   Precise control over catalyst composition and structure is essential for optimizing oxygen reduction reaction (ORR) performance in energy conversion devices. In this study, we design ORR catalysts using the layer-by-layer electrodeposition of Au and Ru on glassy carbon electrodes modified with self-assembled monolayers of metal complexes. Two surface modulation architectures are explored. In the first, we electrodeposit layers of metals using successively appended coordination complexes via multiple rounds of amide coupling. In the second, we utilize a templated method to regenerate thiol-metal coordination for successive layer-by-layer electrodeposition. Both methods offer tunable multi-metal and multi-layer architectures. Cyclic voltammetry and CN⁻poisoning studies confirm metal electrodeposition and catalytic function. Higher order layering of metals significantly enhances ORR performance, and rotating ring-disk electrode measurements show improved selectivity for water over H₂O₂with increasing metal layers. The most selective ORR catalyst for water is a five-layer Au electrode that reduces O₂by an average of 3.6 electrons in neutral media despite bulk Au favoring the two-electron pathway under analogous conditions. This work introduces a flexible and generalizable framework for constructing multi-metal catalysts with a high degree of compositional control, which could have applications in ORR cathodes and other electrocatalytic systems. 

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5. Size-tuned Pt–Ni octahedra for enhanced oxygen reduction reaction performance

   https://doi.org/10.1557/s43580-026-01639-y  

   Delgado, Joseph; Li, Can; Zhao, Bo; Bharathan, Prabhu; Maryam, Areesha; Fang, Jiye (April 2026, MRS Advances)

   Abstract Pt-Ni octahedral nanocrystals with exposed {111} facets are highly active oxygen reduction reaction (ORR) catalysts, yet achieving precise control over their particle size remains challenging. In this work, three Pt-Ni octahedral nanocatalysts with tunable sizes were synthesized using a one-pot colloidal method by adjusting the amount of NiCl₂·6H₂O precursor. Interestingly, both decreasing and increasing the Ni precursor amount relative to the standard value of 0.05 mmol resulted in smaller octahedra. At low precursor concentrations, limited Ni precursor supply restricts crystal growth, whereas at high concentrations, accelerated nucleation and Cl⁻-induced stabilization of the (111) facets inhibit further growth. Electrochemical measurements show that the catalyst exhibiting the smallest particle size delivers the highest ORR mass activity (1.98 A/mg_Pt), likely due to its large specific surface area. This work highlights the crucial role of precursor concentration in tailoring nanoparticle dimensions and enhancing the electrochemical activity of Pt-Ni catalysts for the ORR. Graphical abstract 

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