Diverse Hierarchical Meso/Nanoporous Pt Film Electrocatalysts Prepared via Hydrogen Adsorption-Assisted Dynamic Soft Templating

In this study, we present an innovative approach for creating hierarchical meso/nanoporous Pt films using dynamic soft templating. The fabrication process, called dynamic soft templating, involves Pt electrodeposition within a specialized bicontinuous microemulsion (BME) system characterized by a sophisticated three-dimensional network comprising water and oil phases, surfactants, and cosurfactants. Pt electrodeposition exclusively occurs in the water phase of the BME. This results in a porous Pt film exhibiting a nanostructure mirroring the oil solution/water solution nanostructure (solution/solution structure) of the BME, the size of which can be tailored by adjusting the BME composition. Through a simultaneous interplay of Pt electrodeposition and overpotential deposition of hydrogen (H-OPD, dissociative adsorption of water), potential-dependent Pt mesostructures are dynamically shaped. As a result, we achieve diverse morphologies in the form of hierarchical meso/nanoporous Pt films. The potential applications of the films are evaluated as electrocatalysts for the methanol oxidation reaction (MOR), and it was found that the electrocatalytic performances seem to be sensitive to nanoporosity and not relevant to mesoporosity.

Cost-effective, high-performance Ni3Sn4 electrocatalysts for methanol oxidation reaction in acidic environments

Methanol (CH₃OH) oxidation offers a promising avenue for transitioning to clean energy, particularly in the field of direct methanol fuel cells (DMFCs). However, the development of efficient and cost-effective catalysts for the methanol oxidation reaction (MOR) remains a critical challenge. Herein, we report the exceptional electrocatalytic activity and stability of Ni₃Sn₄ toward MOR in acidic media, achieving a performance comparable to that of commercial Pt/C catalysts. Our catalyst design incorporates Earth-abundant Ni and Sn elements, resulting in a material that is 1800 times more cost-effective than Pt/C. Density functional theory (DFT) modeling substantiates our experimental findings, shedding light on the favorable reaction mechanisms and kinetics on the Ni₃Sn₄ surface. Additionally, the as-synthesized Ni₃Sn₄ electrocatalyst demonstrates commendable durability, maintaining its electrocatalytic activity even after prolonged exposure to harsh acidic conditions.

Modulating the intrinsic properties of platinum–cobalt nanowires for enhanced electrocatalysis of the oxygen reduction reaction

The ability to improve the intrinsic activity of nanoalloy electrocatalysts is essential for designing highly efficient electrocatalysts by optimizing the basic physical properties of the nanoalloy.

Agar-induced hollow porous carbon nanospheres anchored platinum for high-performance hydrogenation

Hollow porous carbon has attracted a great deal of interest as catalyst-support because of its high surface area, low density and large pore volume. Herein, we develop a layer-by-layer assembly method to effectively load Pt nanoparticles on hollow porous carbon nanospheres (Pt/HPC) through using modified-SiO₂ nanospheres as the template and agar as the carbon resource. The gel properties of agar (e.g., sensitivity to temperature and high mechanical strength) makes the Pt nanoparticles well crosslink with carbon, as well as endows the carbon nanospheres with robust stability. The synthesized Pt/HPC was employed as a catalyst in the hydrogenation reduction of rhodamine B (RhB). The catalytic results demonstrate that Pt/HPC is very promising for RhB hydrogenation as compared to commercial Pt/C catalyst. It is proven that such excellent activity of Pt/HPC can be attributed to the combined merits of hollow porous architecture and well combination between HPC and Pt nanoparticles.

Ultrathin-Polyaniline-Coated Pt-Ni Alloy Nanooctahedra for the Electrochemical Methanol Oxidation Reaction

Controlling the morphology and composition of nanocatalysts constructed from metals and conductive polymers has attracted attention owing to their great potential for the development of high-efficiency catalysts for various catalytic applications. Herein, a facile synthetic approach for ultrathin-polyaniline-coated Pt-Ni nanooctahedra (Pt-Ni@PANI hybrids) with controllable PANI shell thicknesses is presented. Pt-Ni nanooctahedra/C catalysts enclosed by PANI shells with thicknesses from 0.6 to 2.4 nm were obtained by fine control over the amount of aniline. The various Pt-Ni@PANI hybrids exhibited electrocatalytic activity toward the methanol oxidation reaction that is highly dependent on the thickness of the PANI shell. Pt-Ni@PANI hybrids with the thinnest PANI shells (0.6 nm) showed markedly improved electrocatalytic performance for the methanol oxidation reaction compared with Pt-Ni@PANI hybrids with thicker PANI shells, Pt-Ni nanooctahedra/C, and commercial Pt/C due to synergistic benefits of ultrathin PANI shells and Pt-Ni alloy.

Porous PdRh nanobowls: facile synthesis and activity for alkaline ethanol oxidation

Optimizing structure and composition with respect to electrocatalytic performance is critical to achieve outstanding Pd-based electrocatalysts. Herein, we have successfully developed a novel electrocatalyst of hollow and porous PdRh nanobowls (PdRh NBs) for the ethanol oxidation reaction (EOR) by using urea as a guiding surfactant. Under alkaline hydrothermal conditions, urea molecules can release bubbles (NH3 and CO2) that in turn guide the formation of PdRh nanobowls. The porous bowl-like structures of PdRh NBs expose abundant surface sites, which allows for increased collision frequency via confining reactants within open spaces. In regards to composition, the reason for introducing Rh is that not only is the redox potential of Rh approximate with that of Pd (beneficial to the formation of high PdRh alloy phase), but also it can effectively facilitate the breakage of C-C bond on the electrode surface (enhancing the total oxidation of ethanol to CO2). Benefiting from the compositional and structural advantages, the newly developed PdRh NBs exhibit significantly improved electrocatalytic activity for the EOR compared with those of the pure Pd NBs, PdRh nanoparticles (PdRh NPs) and commercial Pd black. These attributes might make them good anodic candidates for application in direct ethanol fuel cells.

A novel strategy for the synthesis of hollow Pt–Cu tetradecahedrons as an efficient electrocatalyst toward methanol oxidation

Pt–Cu TNs can be simply achieved within a few minutes by an H⁺-assisted disproportionation reaction using Cu₂O tetradecahedrons as the template. Due to its unique structural advantages, these Pt–Cu TNs exhibit extraordinary electrocatalytic performance toward MOR.

Micelle-Assisted Strategy for the Direct Synthesis of Large-Sized Mesoporous Platinum Catalysts by Vapor Infiltration of a Reducing Agent

Stable polymeric micelles have been demonstrated to serve as suitable templates for creating mesoporous metals. Herein, we report the utilization of a core-shell-corona type triblock copolymer of poly(styrene-b-2-vinylpyridine-b-ethylene oxide) and H₂PtCl₆·H₂O to synthesize large-sized mesoporous Pt particles. After formation of micelles with metal ions, the reduction process has been carried out by vapor infiltration of a reducing agent, 4-(Dimethylamino)benzaldehyde. Following the removal of the pore-directing agent under the optimized temperature, mesoporous Pt particles with an average pore size of 15 nm and surface area of 12.6 m²·g^-1 are achieved. More importantly, the resulting mesoporous Pt particles exhibit superior electrocatalytic activity compared to commercially available Pt black.

Trimetallic PtPdCu nanowires as an electrocatalyst for methanol and formic acid oxidation

PtPdCu nanowires show enhanced electrocatalytic activity and stability compared to their bimetallic counterparts and commercial Pt/C.

Synthesis of a Pt/reduced graphene oxide/polydopamine composite material for localized surface plasmon resonance and methanol electrocatalysis

Pt NPs are synthesized and loaded with rGO onto ITO using polydopamine. The strongest LSPR effect corresponds to the optimal catalyst. The catalyst has a good anti-poison property against CO and shows good cycle stability.