Supported Anionic Gold Nanoparticle Catalysts Modified Using Highly Negatively Charged Multivacant Polyoxometalates

Abstract

Although supported anionic gold nanoparticle catalysts have been theoretically investigated for their efficacy in activating O2 in aerobic oxidation reactions, limited studies have been reported due to the difficulty of designing these catalysts. Herein, we developed a feasible method for preparing supported anionic gold nanoparticle catalysts using multivacant lacunary polyoxometalates with high negative charges. We confirmed the strong and robust electronic interaction between gold nanoparticles and multivacant lacunary polyoxometalates, and the electronic states of the supported gold nanoparticle catalysts can be sequentially modulated. Particularly, the catalyst prepared using [SiW9O34]10− acted as an efficient reusable heterogeneous catalyst, showing superior catalytic performance for the oxidative dehydrogenation of piperidone derivatives to the corresponding enaminones and remarkably higher stability than supported gold nanoparticle catalysts without this modification.

Synthesis of Nitrogen- and Oxygen-Containing Heterocycles Catalysed by Metal Nanoparticles Reported in 2022

“…reported the synthesis of supported anionic AuNPs using a modified Turkevich method involving NaBH 4 mediated reduction of an aqueous solution of HAuCl 4 and sodium silico tungstate (Na 10 SiW 9 O 34 ). 56 Furthermore, a supported SiW9-modified AuNP catalyst was prepared by an impregnation method. TEM images of the NPs demonstrated small sizes of nearly 5 nm.…”

Gold/cobalt ferrite nanocomposite as a potential agent for photothermal therapy

“…Due to its catalytic activity and plasmonic properties, the most common arrangement is that AuNPs are surrounding the core made from different material [46][47][48][49]; however, there are also studies exploring other benefits of having gold as a core [50][51][52]. In order to get the CFO@AuNPs composite, while maintaining current particle size, it would be necessary to modify synthesis process, which would include specific surface functionalization of gold [53] and complementary functionalization of CFO, to assure compatibility of surface agents.…”

Electron Donation from Boron Suboxides via Strong p–d Orbital Hybridization Boosts Molecular O2 Activation on Ru/TiO2 for Low-Temperature Dibromomethane Oxidation

“…19 Since the Ru in Ru/Ti was already mainly in the Ru 0 state, the transferred electrons from B would further enhance the electron density around the Ru atom with negative charges. 36,37 The activation of O 2 is usually through constant single-electron donation from an electron donator into the O 2 2π* antibonding orbital, which weakens the O−O bond to form O* species. 14 The negatively charged Ru with abundant electron density thus acted as the electron donator, complexing with the antibonding orbital of O 2 , weakening the O−O bond to realize the O 2 activation.…”