Tri-metallic PtPdAu mesoporous nanoelectrocatalysts

Carbon-Supported Noble-Metal Nanoparticles for Catalytic Applications—A Review

Noble-metal nanoparticles (NMNPs), with their outstanding properties, have been arousing the interest of scientists for centuries. Although our knowledge of them is much more significant today, and we can obtain NMNPs in various sizes, shapes, and compositions, our interest in them has not waned. When talking about noble metals, gold, silver, and platinum come to mind first. Still, we cannot forget about elements belonging to the so-called platinum group, such as ruthenium, rhodium, palladium, osmium, and iridium, whose physical and chemical properties are very similar to those of platinum. It makes them highly demanded and widely used in various applications. This review presents current knowledge on the preparation of all noble metals in the form of nanoparticles and their assembling with carbon supports. We focused on the catalytic applications of these materials in the fuel-cell field. Furthermore, the influence of supporting materials on the electrocatalytic activity, stability, and selectivity of noble-metal-based catalysts is discussed.

Synthesis and potential applications of trimetallic nanostructures

The present review highlights the synthetic strategies and potential applications of TMNs for organic reactions, environmental remediation, and health-related activities.

Proton-Regulated Catalytic Activity of Nanozymes for Dual-Modal Bioassay of Urease Activity

Benefiting from the merits of high stability and superior activity, nanozymes are recognized as promising alternatives to natural enzymes. Despite the great leaps in the field of therapy and colorimetric sensing, the development of highly sensitive nanozyme-involved photoelectrochemical (PEC) biosensors is still in its infancy. Specifically, the investigation of multifunctional nanozymes facilitating different catalytic reactions remains largely unexplored due to the difficulty in synergistically amplifying the PEC signals. In this work, mesoporous trimetallic AuPtPd nanospheres were synthesized with both efficient oxidase and peroxidase-like activities, which can synergistically catalyze the oxidation of 4-chloro-1-naphthol to produce benzo-4-chlorohexadienone precipitation on the surface of photoactive materials, and thus lead to the decreased photocurrent as well as increased charge-transfer resistance. Inspired by the proton-dependent catalytic activity of nanozymes, a self-regulated dual-modal PEC and electrochemical bioassay of urease activity was innovatively established by in situ regulating the activity of AuPtPd nanozymes through urease-mediated proton-consuming enzymatic reactions, which can remarkably improve the accuracy of the assay. Meanwhile, the determination of urease activity in spiked human saliva samples was successfully realized, indicating the reliability of the biosensor and its application prospects in clinical diagnosis.

Trimetallic PdCuAu Nanoparticles for Temperature Sensing and Fluorescence Detection of H 2 O 2 and Glucose

The design of palladium-based nanostructures has good prospects in various applications. This paper reports a simple one-step synthesis method of PdCuAu nanoparticles (PdCuAu NPs) prepared directly in aqueous solution. PdCuAu NPs have attracted much attention owing to their unique synergistic electronic effect, optical and catalytic performance. As temperature sensor, PdCuAu NPs are sensitive to the fluorescence intensity change in the temperature range of 4-95°C, which is due to its unique optical properties. The prepared PdCuAu NPs have excellent catalytic performance for peroxidase-like enzymes. It can catalyze TMB rapidly in the presence of hydrogen peroxide and oxidize it to visible blue product (oxTMB). Based on its unique peroxidase-like properties, this study used PdCuAu NPs colorimetric platform detection of hydrogen peroxide and glucose. The linear ranges of hydrogen peroxide and glucose were 0.1-300 μM and 0.5-500 μM, respectively, and the detection limits (LOD) were 5 and 25 nM, respectively. This simple and rapid method provides a good prospect for the detection of H2O2 and glucose in practical applications.

Facile Synthesis Of Composition-Controllable PtPdAuTe Nanowires As Superior Electrocatalysts For Direct Methanol Fuel Cells

Multicomponent Pt-based nanowires (NWs) have attracted widespread attention as eletrocatalysts toward direct alcohol fuel cells because of their unique one-dimensional structure and high reaction dynamics. Quaternary PtPdAuTe NWs are designed via a facile template method, and NWs with a different composition are obtained by adjusting the feed ratio of metal precursors. The direct displacement reaction of metal precursors with Te NWs and the partial oxidation of Te lead to the formation of quaternary NWs. The rough surface and abundant reactive sites deriving from the rearrangement of metal atoms on the Te NWs surface endow the PtPdAuTe NWs with a superior electrocatalytic property and durability for methanol oxidation. The Pt₂₀ Pd₂₀ Au₁₀ Te₅₀ NWs display the largest mass activity and best stability among all catalysts. The preparation of PtPdAuTe NWs could provide a viable strategy for the preparation of other multicomponent NWs.

PtPdRh Mesoporous Nanospheres: An Efficient Catalyst for Methanol Electro-Oxidation

Porous multimetallic alloyed nanostructures possess unique physical and chemical properties to generate promising potential in fuel cells. However, the controllable synthesis of this kind of materials still remains challenging. Herein, we report a facile method for the one-pot, high-yield synthesis of trimetallic PtPdRh mesoporous nanospheres (PtPdRh MNs) under mild conditions. The resultant PtPdRh MNs possess the features of uniform shape, a narrow size distribution, plenty of well-defined mesopores, highly open structure, and multicomponent effects, which impart advantages such as large surface area, favorable mass diffusion, high utilization of electrocatalysts, and synergy among the various metal components. Benefitting from the synergetic effects originating from the multimetallic composition and unique mesoporous structure, the as-prepared PtPdRh MNs exhibit remarkably enhanced electrocatalytic performance for methanol oxidation reaction relative to bimetallic PtPd MNs and commercial Pt/C catalyst.

One-step fabrication of bimetallic PtNi mesoporous nanospheres as an efficient catalyst for the oxygen reduction reaction

The controlled synthesis of Pt-based bimetallic porous nanostructures is highly important for the design of electrocatalysts with high performance. Herein, we report a one-step method for the direct synthesis of well-dispersed bimetallic PtNi mesoporous nanospheres (PtNi MNs) at high yield. Benefitting from the synergistic effect of composition (bimetallic PtNi) and structure (mesoporous and highly open structure), the as-obtained PtNi MNs exhibit superior catalytic activity and stability for the oxygen reduction reaction.