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Al-Hilfi S, Jiang X, Heuer J, Akula S, Tammeveski K, Hu G, Yang J, Wang HI, Bonn M, Landfester K, Müllen K, Zhou Y. Single-Atom Catalysts through Pressure-Controlled Metal Diffusion. J Am Chem Soc 2024; 146:19886-19895. [PMID: 38990188 PMCID: PMC11273616 DOI: 10.1021/jacs.4c03066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 06/23/2024] [Accepted: 06/25/2024] [Indexed: 07/12/2024]
Abstract
Single-atom catalysts (SACs) open up new possibilities for advanced technologies. However, a major complication in preparing high-density single-atom sites is the aggregation of single atoms into clusters. This complication stems from the delicate balance between the diffusion and stabilization of metal atoms during pyrolysis. Here, we present pressure-controlled metal diffusion as a new concept for fabricating ultra-high-density SACs. Reducing the pressure inhibits aggregation substantially, resulting in almost three times higher single-atom loadings than those obtained at ambient pressure. Molecular dynamics and computational fluid dynamics simulations reveal the role of a metal hopping mechanism, maximizing the metal atom distribution through an increased probability of metal-ligand binding. The investigation of the active site density by electrocatalytic oxygen reduction validates the robustness of our approach. The first realization of Ullmann-type carbon-oxygen couplings catalyzed on single Cu sites demonstrates further options for efficient heterogeneous catalysis.
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Affiliation(s)
- Samir
H. Al-Hilfi
- School
of Materials Science and Engineering, Jiangsu
University, Zhenjiang 212013, Jiangsu, China
- Max
Planck Institute for Polymer Research, 55128 Mainz, Germany
| | - Xikai Jiang
- State
Key Laboratory of Nonlinear Mechanics, Institute
of Mechanics, Chinese Academy of Science, Beijing 100190, China
| | - Julian Heuer
- Max
Planck Institute for Polymer Research, 55128 Mainz, Germany
| | - Srinu Akula
- Institute
of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Kaido Tammeveski
- Institute
of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Guoqing Hu
- Department
of Engineering Mechanics, State Key Laboratory of Fluid Power and
Mechatronic Systems, Zhejiang University, Hangzhou 310027, Zhejiang, China
| | - Juan Yang
- School
of Materials Science and Engineering, Jiangsu
University, Zhenjiang 212013, Jiangsu, China
| | - Hai. I. Wang
- Max
Planck Institute for Polymer Research, 55128 Mainz, Germany
- Nanophotonics,
Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584 CC Utrecht, The Netherlands
| | - Mischa Bonn
- Max
Planck Institute for Polymer Research, 55128 Mainz, Germany
| | | | - Klaus Müllen
- Max
Planck Institute for Polymer Research, 55128 Mainz, Germany
| | - Yazhou Zhou
- School
of Materials Science and Engineering, Jiangsu
University, Zhenjiang 212013, Jiangsu, China
- Max
Planck Institute for Polymer Research, 55128 Mainz, Germany
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2
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Sun Y, Mendelev MI, Zhang F, Liu X, Da B, Wang CZ, Wentzcovitch RM, Ho KM. Unveiling the effect of Ni on the formation and structure of Earth's inner core. Proc Natl Acad Sci U S A 2024; 121:e2316477121. [PMID: 38236737 PMCID: PMC10823253 DOI: 10.1073/pnas.2316477121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 12/09/2023] [Indexed: 02/01/2024] Open
Abstract
Ni is the second most abundant element in the Earth's core. Yet, its effects on the inner core's structure and formation process are usually disregarded because of its electronic and size similarity with Fe. Using ab initio molecular dynamics simulations, we find that the bcc phase can spontaneously crystallize in liquid Ni at temperatures above Fe's melting point at inner core pressures. The melting temperature of Ni is shown to be 700 to 800 K higher than that of Fe at 323 to 360 GPa. hcp, bcc, and liquid phase relations differ for Fe and Ni. Ni can be a bcc stabilizer for Fe at high temperatures and inner core pressures. A small amount of Ni can accelerate Fe's crystallization at core pressures. These results suggest that Ni may substantially impact the structure and formation process of the solid inner core.
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Affiliation(s)
- Yang Sun
- Department of Physics, Xiamen University, Xiamen361005, China
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY10027
- Department of Physics, Iowa State University, Ames, IA50011
| | | | - Feng Zhang
- Department of Physics, Iowa State University, Ames, IA50011
| | - Xun Liu
- Center for Basic Research on Materials, National Institute for Materials Science, Ibaraki305-0044, Japan
| | - Bo Da
- Center for Basic Research on Materials, National Institute for Materials Science, Ibaraki305-0044, Japan
| | | | - Renata M. Wentzcovitch
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY10027
- Department of Earth and Environmental Sciences, Columbia University, New York, NY10027
- Lamont–Doherty Earth Observatory, Columbia University, Palisades, NY10964
- Data Science Institute, Columbia University, New York, NY10027
- Center for Computational Quantum Physics, Flatiron Institute, New York, NY10010
| | - Kai-Ming Ho
- Department of Physics, Iowa State University, Ames, IA50011
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3
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Gispen W, Dijkstra M. Brute-force nucleation rates of hard spheres compared with rare-event methods and classical nucleation theory. J Chem Phys 2023; 159:086101. [PMID: 37638626 DOI: 10.1063/5.0165159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 08/09/2023] [Indexed: 08/29/2023] Open
Abstract
We determine nucleation rates of hard spheres using brute-force molecular dynamics simulations. We overcome nucleation barriers of up to 28 kBT, leading to a rigorous test of nucleation rates obtained from rare-event methods and classical nucleation theory. Our brute-force nucleation rates show excellent agreement with umbrella sampling simulations by Filion et al. [J. Chem. Phys. 133, 244115 (2010)] and seeding simulations by Espinosa et al. [J. Chem. Phys. 144, 034501 (2016)].
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Affiliation(s)
- Willem Gispen
- Soft Condensed Matter and Biophysics, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584 CC Utrecht, Netherlands
| | - Marjolein Dijkstra
- Soft Condensed Matter and Biophysics, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584 CC Utrecht, Netherlands
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4
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Pang G, Koper KD, Wu SM, Wang W, Lasbleis M, Euler G. Enhanced inner core fine-scale heterogeneity towards Earth's centre. Nature 2023; 620:570-575. [PMID: 37407825 DOI: 10.1038/s41586-023-06213-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Accepted: 05/12/2023] [Indexed: 07/07/2023]
Abstract
Earth's inner core acquires texture as it solidifies within the fluid outer core. The size, shape and orientation of the mostly iron grains making up the texture record the growth of the inner core and may evolve over geologic time in response to geodynamical forces and torques1. Seismic waves from earthquakes can be used to image the texture, or fabric, of the inner core and gain insight into the history and evolution of Earth's core2-6. Here, we observe and model seismic energy backscattered from the fine-scale (less than 10 km) heterogeneities7 that constitute inner core fabric at larger scales. We use a novel dataset created from a global array of small-aperture seismic arrays-designed to detect tiny signals from underground nuclear explosions-to create a three-dimensional model of inner core fine-scale heterogeneity. Our model shows that inner core scattering is ubiquitous, existing across all sampled longitudes and latitudes, and that it substantially increases in strength 500-800 km beneath the inner core boundary. The enhanced scattering in the deeper inner core is compatible with an era of rapid growth following delayed nucleation.
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Affiliation(s)
- Guanning Pang
- Department of Geology and Geophysics, University of Utah, Salt Lake City, UT, USA.
- Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY, USA.
| | - Keith D Koper
- Department of Geology and Geophysics, University of Utah, Salt Lake City, UT, USA
| | - Sin-Mei Wu
- Department of Geology and Geophysics, University of Utah, Salt Lake City, UT, USA
- Swiss Seismological Service, ETH Zurich, Zurich, Switzerland
| | - Wei Wang
- Department of Earth Sciences, University of Southern California, Los Angeles, CA, USA
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China
| | - Marine Lasbleis
- Laboratoire de Planétologie et Géosciences, UMR 6112, Université de Nantes, CNRS, Nantes, France
- Bureau Veritas Marine & Offshore, Paris La Défense, France
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5
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Ghosh M, Zhang S, Hu L, Hu SX. Cooperative diffusion in body-centered cubic iron in Earth and super-Earths' inner core conditions. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2023; 35:154002. [PMID: 36753774 DOI: 10.1088/1361-648x/acba71] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 02/08/2023] [Indexed: 06/18/2023]
Abstract
The physical chemistry of iron at the inner-core conditions is key to understanding the evolution and habitability of Earth and super-Earth planets. Based on full first-principles simulations, we report cooperative diffusion along the longitudinally fast⟨111⟩directions of body-centered cubic (bcc) iron in temperature ranges of up to 2000-4000 K below melting and pressures of ∼300-4000 GPa. The diffusion is due to the low energy barrier in the corresponding direction and is accompanied by mechanical and dynamical stability, as well as strong elastic anisotropy of bcc iron. These findings provide a possible explanation for seismological signatures of the Earth's inner core, particularly the positive correlation between P wave velocity and attenuation. The diffusion can also change the detailed mechanism of core convection by increasing the diffusivity and electrical conductivity and lowering the viscosity. The results need to be considered in future geophysical and planetary models and should motivate future studies of materials under extreme conditions.
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Affiliation(s)
- Maitrayee Ghosh
- Laboratory for Laser Energetics, University of Rochester, Rochester, NY 14623, United States of America
- Department of Chemistry, University of Rochester, Rochester, NY 14611, United States of America
| | - Shuai Zhang
- Laboratory for Laser Energetics, University of Rochester, Rochester, NY 14623, United States of America
| | - Lianming Hu
- Laboratory for Laser Energetics, University of Rochester, Rochester, NY 14623, United States of America
- Department of Mechanical Engineering, University of Rochester, Rochester, NY 14611, United States of America
| | - S X Hu
- Laboratory for Laser Energetics, University of Rochester, Rochester, NY 14623, United States of America
- Department of Mechanical Engineering, University of Rochester, Rochester, NY 14611, United States of America
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Early Cambrian renewal of the geodynamo and the origin of inner core structure. Nat Commun 2022; 13:4161. [PMID: 35853855 PMCID: PMC9296475 DOI: 10.1038/s41467-022-31677-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 06/20/2022] [Indexed: 11/08/2022] Open
Abstract
Paleomagnetism can elucidate the origin of inner core structure by establishing when crystallization started. The salient signal is an ultralow field strength, associated with waning thermal energy to power the geodynamo from core-mantle heat flux, followed by a sharp intensity increase as new thermal and compositional sources of buoyancy become available once inner core nucleation (ICN) commences. Ultralow fields have been reported from Ediacaran (~565 Ma) rocks, but the transition to stronger strengths has been unclear. Herein, we present single crystal paleointensity results from early Cambrian (~532 Ma) anorthosites of Oklahoma. These yield a time-averaged dipole moment 5 times greater than that of the Ediacaran Period. This rapid renewal of the field, together with data defining ultralow strengths, constrains ICN to ~550 Ma. Thermal modeling using this onset age suggests the inner core had grown to 50% of its current radius, where seismic anisotropy changes, by ~450 Ma. We propose the seismic anisotropy of the outermost inner core reflects development of a global spherical harmonic degree-2 deep mantle structure at this time that has persisted to the present day. The imprint of an older degree-1 pattern is preserved in the innermost inner core. New single crystal paleointensity data show that the geomagnetic field was renewed in the early Cambrian after near collapse in the Ediacaran Period. This implies that the innermost/outermost structure of the inner core formed 450 million yrs. ago.
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