Synthesis of Ultrasmall Platinum Nanoparticles on Polymer Nanoshells for Size-Dependent Catalytic Oxidation Reactions

Abstract

It is highly desirable for the synthesis and stabilization of noble metal nanoparticles of uniform, precisely tunable sizes, especially in the range of angstroms to a few nanometers, for many catalytic applications in pursuit of optimal activity and selectivity. Herein, we report a novel strategy for the synthesis of uniform platinum (Pt) nanoparticles of ultrasmall sizes (average size: 0.9-2.3 nm), which are stabilized on hollow polymer nanoshells formed by polymerization of sodium dodecyl benzenesulfonate (SDBS) at the interface of an ethanol/water emulsion. The resulting composite represents a highly active catalyst for effective oxidation of alcohols under ambient conditions. Strong size-dependent catalytic activity of Pt nanoparticles has been revealed in aerobic oxidation of 1-phenylethanol to yield acetophenone, demonstrating a volcano-shape profile, with Pt nanoparticles of ∼1.7 nm showing the highest activity. The size effect has been attributed to the size-dependent d-band electron structure of the Pt nanoparticles. This work reveals the size effect of Pt nanoparticles in general organic oxidation reactions, and thus provides a general methodology and a lot of opportunities in the design of metal-nanoparticle-based catalysts for fine-chemical production.

Rapid synthesis of ultrasmall platinum nanoparticles supported on macroporous cellulose fibers for catalysis

“…There are many reported methods for the decoration of ultrasmall platinum nanoparticles on various support materials such as polymer nanoshells, carbon, and nanostructured gold. [33][34][35] However, these methods are more sophisticated, need multiple steps, require a variety of chemicals, and long preparation time. As a result, these methods may not be adaptable for large-scale synthesis in the industry.…”

“…Noble metal nanoparticles (NPs) possess extraordinary catalytic properties that are highly dependent on their size, shape, and composition. [1][2][3][4][5] As a result, noble metal NPs are extensively utilized for a number of chemical transformations such as de/ hydrogenations, 6,7 oxidation, 8 alkylation, 9 and coupling reactions. 10 Recently, noble metal NP-based catalytic processes have become intriguing and effective methods for water or wastewater treatment technologies.…”

‘Dip Catalysts’ Based on Polymer‐Metal Nanocomposite Thin Films: Combining Soft‐Chemical Fabrication with Efficient Application and Monitoring

“…Catalytic applications of polymer‐metal nanocomposites, especially in the colloidal form, are well‐known; combination of the catalytic properties of metal nanoparticles and the unique characteristics of polymers have found use in a variety of reactions including hydrogenation of olefins, dehydration of isopropyl alcohol, methanol oxidation, hydrogenation of aromatic nitro compounds and Suzuki‐Miyaura coupling ,. Polymer‐metal core‐shell structures have been shown to be efficient catalysts for hydrogenation of 4‐nitrophenol and quinoline, and aerobic oxidation of alcohol; specific examples include Pt nanoparticles on a resin layer formed on solid silica spheres, hollow polymer nanoshells with Pt nanoparticles on the surface, and Au and Ag−Au nanoparticles loaded on polymer microspheres . The powder and colloidal forms of the nanocomposites are restrictive in terms of handling, recovery and reuse as catalysts.…”

The Size‐Dependent Catalytic Performances of Supported Metal Nanoparticles and Single Atoms for the Upgrading of Biomass‐Derived 5‐Hydroxymethylfurfural, Furfural, and Levulinic acid

“…It is because of the upward shift of the d-band center, facilitating optimal interaction between the active sites and guest molecule. [11] For certain chemical transformations, both geometric and electronic effects have been found to operate within a certain size range. [12][13] The single-atom catalysts have recently emerged as a new frontier in heterogeneous catalysis, affording very high specific activity and selectivity due to 100 % metal dispersion and the presence of a single type of metal site.…”