Abstract
Evaluation of metal nanoparticle catalysts functionalized with well-defined thiolate ligands can be potentially important because such systems can provide a spatial control in the reactivity and selectivity of catalysts. A synthetic method utilizing Bunte salts (sodium S-alkylthiosulfates) allows the formation of metal nanoparticles (Au, Ag, Pd, Pt, and Ir) capped with alkanethiolate ligands. The catalysis studies on Pd nanoparticles show a strong correlation between the surface ligand structure/composition and the catalytic activity and selectivity for the hydrogenation/isomerization of alkenes, dienes, trienes, and allylic alcohols. The high selectivity of Pd nanoparticles is driven by the controlled electronic properties of the Pd surface limiting the formation of Pd–alkene adducts (or intermediates) necessary for (additional) hydrogenation. The synthesis of water soluble Pd nanoparticles using ω-carboxylate-S-alkanethiosulfate salts is successfully achieved and these Pd nanoparticles are examined for the hydrogenation of various unsaturated compounds in both homogeneous and heterogeneous environments. Alkanethiolate-capped Pt nanoparticles are also successfully synthesized and further investigated for the hydrogenation of various alkynes to understand their geometric and electronic surface properties. The high catalytic activity of activated terminal alkynes, but the significantly low activity of internal alkynes and unactivated terminal alkynes, are observed for Pt nanoparticles.
Highlights
Research on nanomaterials has been popular for more than two decades since they exhibit unique electrical, optical, and physical properties compared to their counterpart bulk materials [1,2,3,4]
The synthesis of metal nanoparticles has drawn a lot of attention due to their size, shape, and surface-state dependent properties in various applications such as catalysis
Investigating the performance of small metal nanoparticle catalysts influenced by the presence of well-defined organic ligands resembling amino acid residues in an enzyme binding pocket can provide understanding of the effects of steric, noncovalent, and chiral interactions in the near-surface environment
Summary
Research on nanomaterials has been popular for more than two decades since they exhibit unique electrical, optical, and physical properties compared to their counterpart bulk materials [1,2,3,4]. The presence of [TOA][AuX2] (TOA: tetraoctylammonium) species was found to favor the formation of small monodispersed nanoparticles, whereas the large excess of gold(I) thiolate species does not These mechanistic studies confirmed the importance of understanding the role of the intermediates and the key precursor species present throughout the Brust–Schiffrin two-phase reactions. The drawback of thiolate-stabilized nanoparticles synthesized using the Brust–Schiffrin method was that the thiol ligands form a densely packed monolayer, which in turn inhibits the catalytic activity of the metal surface [50,51]. These main sections are followed by Conclusion and Perspectives with a brief comment on future prospects
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
