Absorption of hydrogen by palladium causes PdH to become superconducting below [Formula: see text]. Due to the presence of one octapore and two tetrapores per each Pd atom, it is believed that [Formula: see text] of PdH[Formula: see text] should increase further. Here, using ab initio calculation we show that (i) H placed in tetrapores of PdH[Formula: see text] induces a wide optical gap in the phonon density of states, which significantly reduces the electron-phonon coupling, and that (ii) the energetically preferable octapores filled by H enable the 9 K superconductivity only. This scenario may close a long-standing problem of the high-[Formula: see text] palladium hydrides. Moreover, simulating the pore population by H and D, within ab initio molecular dynamics, we are able to explain the inverse isotope effect in the framework of the Bardeen-Cooper-Schrieffer theory.
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http://dx.doi.org/10.1088/1361-648X/aaf5b0 | DOI Listing |
Molecules
January 2025
Department of Chemistry, National Dong Hwa University, Hualien 97401, Taiwan.
Palladium-doped silver nanoclusters (NCs) have been highlighted for their unique physicochemical properties and potential applications in catalysis, optics, and electronics. Anion-directed synthesis offers a powerful route to control the morphology and properties of these NCs. Herein, we report a novel Pd-doped Ag NC, [Pd(H)Ag(S){SP(OPr)}] (), synthesized through the inclusion of sulfide and hydride anions.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-10691 Stockholm, Sweden.
Direct cross-coupling reactions between two similar unactivated partners are challenging but constitute a powerful strategy for the creation of new carbon-carbon bonds in organic synthesis. [4]Dendralenes are a class of acyclic branched conjugated oligoenes with great synthetic potential for the rapid generation of structural complexity, yet the chemistry of [4]dendralenes remains an unexplored field due to their limited accessibility. Herein, we report a highly selective palladium-catalyzed oxidative cross-coupling of two allenes with the presence of a directing olefin in one of the allenes, enabling the facile synthesis of a broad range of functionalized [4]dendralenes in a convergent modular manner.
View Article and Find Full Text PDFAnal Chem
December 2024
Paul Scherrer Institut, Center for Energy and Environmental Science, CH-5232 Villigen, Switzerland.
X-ray absorption spectroscopy (XAS) is a powerful technique that provides information about the electronic and local geometric structural properties of newly developed electrocatalysts, especially when it is performed under operating conditions (i.e., ).
View Article and Find Full Text PDFChem Sci
December 2024
Centre for Membrane Separations, Adsorption, Catalysis and Spectroscopy for Sustainable Solutions (cMACS), KU Leuven 3001 Leuven Belgium
Palladium(ii)-catalyzed dehydrogenative coupling of aliphatic olefins would enable an efficient route to (conjugated) dienes, but remains scarcely investigated. Here, 2-hydroxypyridine (2-OH-pyridine) was found to be an effective ligand for Pd(ii) in the activation of vinylic C(sp)-H bonds. While reoxidation of Pd(0) is challenging in many catalytic oxidations, one can avoid in this reaction that the reoxidation becomes rate-limiting, even under ambient O pressure, by working in coordinating solvents.
View Article and Find Full Text PDFJ Colloid Interface Sci
March 2025
Key Lab for Colloid and Interface Science of Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China. Electronic address:
Metal hydrides are sensitive to HO and O, which reduces the atom efficiency of the hydride donors. Silver (Ag) is an inexpensive coinage metal; however, its lower activity compared to gold, platinum, and palladium limits its application in catalytic hydrogenation. Here, electron-deficient metallic single-atom Ag (AgSA) was loaded onto γ-AlO using a benzoquinone- and KNO- assisted photolysis approach.
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