Effecting the synergistic function of single metal atom sites and their supports is of great importance to achieve high-performance catalysts. Herein, we successfully fabricate polyoxometalates (POMs)-stabilized atomically dispersed platinum sites by employing three-dimensional metal-organic frameworks (MOFs) as the finite spatial skeleton to govern the accessible quantity, spatial dispersion, and mobility of metal precursors around each POM unit. The isolated single platinum atoms (Pt) are steadily anchored in the square-planar sites on the surface of monodispersed Keggin-type phosphomolybdic acid (PMo) in the cavities of various MOFs, including MIL-101, HKUST-1, and ZIF-67. In contrast, either the absence of POMs or MOFs yielded only platinum nanoparticles. Pt-PMo@MIL-101 are seven times more active than the corresponding nanoparticles in the diboration of phenylacetylene, which can be attributed to the synergistic effect of the preconcentration of organic reaction substrates by porous MOFs skeleton and the decreased desorption energy of products on isolated Pt atom sites.
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http://dx.doi.org/10.1038/s41467-021-24513-x | DOI Listing |
Phys Chem Chem Phys
January 2025
The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan.
Formic acid (HCOOH) is one of the essential molecules for CO utilization including methanol synthesis and hydrogen carriers. In this study, we have investigated the chemical processes of hydrogen and HCOOH on a dilute-alloy Pd-Cu(111) surface using high-resolution X-ray photoelectron spectroscopy (HR-XPS) and density functional theory (DFT) calculations. The present Pd-Cu(111) surface was prepared at 500 K, and the observed core-level shifts of Pd 3d indicate that Pd atoms were located at the surface and subsurface sites: 335.
View Article and Find Full Text PDFDalton Trans
January 2025
Laboratory for Molecular & Functional Design, Department of Engineering, Nara Women's University, Nara 630-8506, Japan.
Rational molecular design afforded fluorescent Cd sensors based on bisquinoline derivatives. Introduction of three methoxy groups at the 5,6,7-positions of the quinoline rings of BQDMEN (,'-bis(2-quinolylmethyl)-,'-dimethylethylenediamine) resulted in the reversal of metal ion selectivity in fluorescence enhancement from zinc to cadmium. Introduction of bulky alkyl groups and an ,-bis(2-quinolylmethyl)amine structure, as well as replacement of one of the two tertiary amine binding sites with an oxygen atom and the use of a 1,2-phenylene backbone significantly improved the Cd specificity.
View Article and Find Full Text PDFAdv Sci (Weinh)
December 2024
School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, 200237, P. R. China.
Precious metal-based single-atom catalysts (PM-SACs) hosted in N-doped carbon supports have shown new opportunities to revolutionize cathodic oxygen reduction reaction (ORR). However, stabilizing the high density of PM-N sites remains a challenge, primarily due to the inherently high free energy of isolated metal atoms, predisposing them to facile atomic agglomeration. Herein, a molten salt-assisted synthesis strategy is proposed to prepare porous PM/N-C (PM = Ru, Pt, and Pd) electrocatalysts with densely accessible PM-N sites.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea.
Enzymes, composed of earth-abundant elements, outperform conventional heterogeneous photocatalysts in hydrogen production due to the dual-site cooperation between adjacent active metal sites and proton-transferring ligands. However, the realization of such dual-site cooperation in heterogeneous catalytic systems is hindered by the challenges in the precise construction of cooperative active sites. In this study, we present the design of a structurally tuned metal-organic framework (MOF) photocatalyst that incorporates cooperative Brønsted acid-single atom catalytic sites.
View Article and Find Full Text PDFLangmuir
December 2024
Department of Chemistry, Carnegie Mellon University, 4400 Avenue, Pittsburgh, Pennsylvania 15213, United States.
Structurally tailored and engineered macromolecular (STEM) networks are attractive materials for soft robotics, stretchable electronics, tissue engineering, and 3D printing due to their tunable properties. To date, STEM networks have been synthesized by atom transfer radical polymerization (ATRP) or the combination of reversible addition-fragmentation chain-transfer (RAFT) polymerization and ATRP. RAFT polymerization could have limited selectivity with ATRP inimer sites that can participate in radical-transfer processes.
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