Using aberration-corrected scanning transmission electron microscopy (STEM), we imaged iridium atoms in isolated iridium complexes in the one-dimensional nonintersecting 14-ring channels of zeolite SSZ-53. STEM allows tracking of the movement of atoms in the channels, demonstrating the interaction of iridium with the zeolite framework (channel confinement) and providing a direct visualization of the initial steps of metal nanocluster formation. The results demonstrate how STEM can be used to help design improved catalysts by identifying the catalytic sites and observing how they change in reactive atmospheres.
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http://dx.doi.org/10.1021/nl2034305 | DOI Listing |
J Am Chem Soc
March 2025
School of Chemistry, The University of New South Wales, Sydney, New South Wales 2052, Australia.
The presence of defects can significantly improve catalytic activity and stability, as they influence the binding of the reactants, intermediates, and products to the catalyst. Controlling defects in the structures of nanocrystal catalysts is synthetically challenging. In this study, we demonstrate the ability to control the growth of Ir nanocrystals, enabling the tuning of both structural and surface defects.
View Article and Find Full Text PDFACS Nano
March 2025
Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States.
Redox transformations at metal oxide (MO)/solution interfaces are broadly important, and oxygen atom transfer (OAT) is one of the simplest and most fundamental examples of such reactivity. OAT is a two-electron transfer process, well-known in gas/solid reactions and catalysis. However, OAT is rarely directly observed at oxide/water interfaces, whose redox reactions are typically proposed to occur in one-electron steps.
View Article and Find Full Text PDFSmall
March 2025
Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
Fine control over the Ir precursor to the Nickel-based layered double hydroxides (LDHs) is significant for decorating both single atoms (SA) and nanoclusters (NC), thus modulating catalytic kinetics and improving overall performance. In this study, NiMn-LDH is synthesized and co-decorated it with Iridium, introducing a new pathway for developing efficient bifunctional electrocatalysts in water-splitting technologies. Additionally, a typical fibrous material has developed by immobilizing.
View Article and Find Full Text PDFMolecules
February 2025
Department of Chemistry, Faculty of Pharmacy, Medical University-Sofia, 1000 Sofia, Bulgaria.
Iridium complexes attract a lot of attention as highly promising antitumor agents due to their various structures, which offer the modification of their physicochemical and biological effects. Compared to conventional platinum-based drugs, iridium complexes are commonly thought to be more active in tumors, resistant to platinum agents and more stable in air and moisture conditions. Chloridoiridium complexes offer a range of advantages facilitating their rational design, reactivity and photochemical activity, leading to different cytotoxic profiles, diverse mechanisms of action and specific intracellular organelles as targets.
View Article and Find Full Text PDFACS Nano
March 2025
State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, P. R. China.
Ruthenium (Ru)-based catalysts have demonstrated promising utilization potentiality to replace the much expensive iridium (Ir)-based ones for proton exchange membrane water electrolysis (PEMWE) due to their high electrochemical activity and low cost. However, the susceptibility of RuO-based materials to easily be oxidized to high-valent and soluble Ru species during the oxygen evolution reaction (OER) in acid media hinders the practical application, especially under current density above 500 mA cm. Here, a manganese-doped RuO catalyst with the hydroxylated metal sites (i.
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