Molecular metal complexes on supports have drawn wide attention as catalysts offering new properties and opportunities for precise synthesis to make uniform catalytic species that can be understood in depth. Here we highlight advances in research with catalysts that are a step more complex than those incorporating single, isolated metal atoms on supports. These more complex catalysts consist of supported noble metal clusters and supported metal oxide clusters, and our emphasis is placed on some of the simplest and best-defined of these catalysts, made by precise synthesis, usually with organometallic precursors. Characterization of these catalysts by spectroscopic, microscopic, and theoretical methods is leading to rapid progress in fundamental understanding of catalyst structure and function, and to expansion of this class of materials. The simplest supported metal clusters incorporate two metal atoms each-they are pair-site catalysts. These and clusters containing several metal atoms have reactivities determined by the metal nuclearity, the ligands on the metal, and the supports, which themselves are ligands. Metal oxide clusters are also included in the discussion presented here, with Zr6O8 clusters that are nodes in metal-organic frameworks being among those that are understood the best. The surface and catalytic chemistries of these metal oxide clusters are distinct from those of bulk zirconia. A challenge in using any supported cluster catalysts is associated with their possible sintering, and recent research shows how metal nanoparticles can be encapsulated in sheaths with well-defined porous structures-zeolites-that make them highly resistant to sintering.
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http://dx.doi.org/10.1039/c8fd00076j | DOI Listing |
Environ Sci Pollut Res Int
January 2025
Council for Geoscience, Private Bag X112, Pretoria, 0001, South Africa.
One-step high-pressure and high-temperature direct aqueous mineral carbonation of tailings derived from mining of Platinum Group Metals in South Africa requires a fundamental understanding of the reactivity of the most dominant mineral phases, i.e. pyroxene and plagioclase (66 wt.
View Article and Find Full Text PDFArch Microbiol
January 2025
Aquatic Animal Health Laboratory, PG & Research Department of Zoology, C. Abdul Hakeem College, Melvisharam, Ranipet, Tamil Nadu, 632509, India.
Salmon calcitonin is a small peptide hormone synthesised and released by a specialised gland called ultimobranchial gland in fish. This hormone has been used to treat osteoporosis for over 50 years. The aim of this study was to compare the efficacy of five repeats of salmon calcitonin (5sCT) produced in two different hosts (bacteria and fish cell line).
View Article and Find Full Text PDFOrg Lett
January 2025
State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China.
A modular synthesis method for 1,4-diketones has been developed. Utilizing inexpensive carboxylic acid esters as carbonyl sources and tetraborylethane () as a nucleophilic reagent, a one-pot strategy for constructing two C-C bonds was established. Notably, this reaction proceeds without the involvement of transition metals and exhibits excellent functional group compatibility.
View Article and Find Full Text PDFNano Lett
January 2025
School of Chemical Engineering and Technology, State Key Laboratory of Chemical Engineering, International Joint Laboratory of Low-carbon Chemical Engineering of Ministry of Education, Tianjin University, Tianjin 300072, P. R. China.
Molybdenum disulfide (MoS) is a promising anode for sodium-ion batteries (SIBs) due to its high theoretical capacity and layered structure. However, a poor reversible conversion reaction and a low initial Coulombic efficiency (ICE) limit its practical application. This study systematically investigated the potential of pre-intercalated sodium ions molybdenum disulfide (Na-MoS) as an anode material for SIBs.
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