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Huang B, Zhang H, Geng L, Luo Z. An Open-Shell Superatom Cluster Ta 10- with Enhanced Stability by United d-d π Bonds and d-Orbital Superatomic States. J Phys Chem Lett 2022; 13:9711-9717. [PMID: 36220259 DOI: 10.1021/acs.jpclett.2c02410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
We carried out a comprehensive study on the gas-phase reactions of Tan- (n = 5-27) with nitrogen using a customized reflection time-of-flight mass spectrometer coupled with a velocity map imaging apparatus (Re-TOFMS-VMI). Among the studied tantalum clusters, Ta10- exhibits prominent mass abundance indicative of its unique inertness. DFT calculation results revealed a D4d bipyramidal prolate structure of the most stable Ta10-, which was verified by photoelectron spectroscopy experiments. The calculations also unveiled that Ta10- has the largest HOMO-LUMO gap and second-order difference of binding energy among the studied clusters. This is associated with its well-organized superatomic orbitals, which consist of both 6s and 5d orbitals of tantalum atoms, allowing for splitting of superatomic 1D and 2P orbitals and an enlarged gap between the singly occupied molecular orbital (SOMO) and unoccupied β counterpart, which brings forth stabilization energy pertaining to Jahn-Teller distortion. Also, the SOMO exhibits a united d-d π orbital pattern that embraces the central Ta8- moiety.
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Affiliation(s)
- Benben Huang
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory of Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hanyu Zhang
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory of Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Lijun Geng
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhixun Luo
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory of Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
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Zhang H, Zhang M, Jia Y, Geng L, Yin B, Li S, Luo Z, Pan F. Vanadium Cluster Neutrals Reacting with Water: Superatomic Features and Hydrogen Evolution in a Fishing Mode. J Phys Chem Lett 2021; 12:1593-1600. [PMID: 33545005 DOI: 10.1021/acs.jpclett.0c03809] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Hydrogen evolution reaction (HER) is known as the heart of various energy storage and conversation systems of renewable energy sources. Here we observe the cluster reactions of a light transition metal, vanadium, with water in a gas-phase flow tube reactor. While HER products of V1 and V2 were not observed, the effective HER of water on neutral Vn (n ≥ 3) clusters reveals reasonable and size-dependent reactivity of the vanadium clusters. Superatomic features and reaction dynamics of V10, V13, and V16 are highlighted. Among the three typical superatoms, V10 and V16 exhibit an abnormal superatomic orbital energy level order, 1S|2S|1P|1D..., where the energy-reduced 2S orbital helps to accommodate the geometric structure and hence reinforce the cluster stability. In comparison, V13 bears a less symmetrical structure and reacts readily with water, allowing for recombination of a hydroxyl atom with an adsorbed hydrogen atom, akin to a fishing-mode HER process. The joint experimental and theoretical study on neutral Vn clusters clarifies the availability of superatom chemistry for transition metals and appeals further development of cluster theory based on electronic cloud/orbital analysis instead of simply counting the valence electrons. Also, we provide insights into the HER mechanism of metal clusters and propose a strategy to design new materials for portable fuel cells of hydrogen energy.
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Affiliation(s)
- Hanyu Zhang
- Beijing National Laboratory of Molecular sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Mingzheng Zhang
- School of Advanced Materials, Peking University Shenzhen Graduate School, Shenzhen 518055, P. R. China
| | - Yuhan Jia
- Beijing National Laboratory of Molecular sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Lijun Geng
- Beijing National Laboratory of Molecular sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Baoqi Yin
- Beijing National Laboratory of Molecular sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Shunning Li
- School of Advanced Materials, Peking University Shenzhen Graduate School, Shenzhen 518055, P. R. China
| | - Zhixun Luo
- Beijing National Laboratory of Molecular sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Feng Pan
- School of Advanced Materials, Peking University Shenzhen Graduate School, Shenzhen 518055, P. R. China
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Zhou Y, Yu X, Cheng L. Multiple d-d bonds between early transition metals in TM 2Li n (TM = Sc, Ti) superatomic molecule clusters. NANOSCALE 2020; 12:20506-20512. [PMID: 33026386 DOI: 10.1039/d0nr05480a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The synthesis and application of compounds with Cr-Cr and V-V d-d quintuple bonds (σ, 2π, 2δ) have led to new thinking about whether d-d multiple bonds also exist between early transition metals such as Sc-Sc and Ti-Ti. In this study, by extensive unbiased global search at the density functional theory level, the low-energy structures of 26e and 30e TM2Lin clusters were obtained. Based on the super valence bond (SVB) theory, the prolate double-core structure of TM2Lin clusters was regarded as a superatomic molecule, of which each half was regarded as an open-shell superatom, and the electronic shell-closure was realized by forming multiple bonds between superatoms. Then, the quintuple super bonds (2δ, 2π, σ) of the Li18Ti2, Li20Sc2, [Li17V2]+, [Li17Ti2]- clusters and the triple super bonds (2π, σ) of the Li24Sc2 and Li24Y2 clusters were confirmed via chemical-bonding analysis. This way of forming multiple bonds between early transition metals through superatomic bonding has promoted the experimental synthesis and application of early transition metal multiple bond compounds.
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Affiliation(s)
- Yichun Zhou
- Department of Chemistry, Key Laboratory of Functional Inorganic Materials of Anhui Province, Anhui University Hefei, Anhui 230601, P. R. China.
| | - Xinlei Yu
- Department of Chemistry, Key Laboratory of Functional Inorganic Materials of Anhui Province, Anhui University Hefei, Anhui 230601, P. R. China.
| | - Longjiu Cheng
- Department of Chemistry, Key Laboratory of Functional Inorganic Materials of Anhui Province, Anhui University Hefei, Anhui 230601, P. R. China.
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Gilmour JTA, Gaston N. Design of superatomic systems: exploiting favourable conditions for the delocalisation of d-electron density in transition metal doped clusters. Phys Chem Chem Phys 2020; 22:18585-18594. [PMID: 32785393 DOI: 10.1039/d0cp01780a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The incorporation of transition metals into superatomic species has led to the proposal of highly tailorable systems, with the transition metal atoms typically acting as magnetic dopants. However, the extent to which d-electrons are able to delocalise from their ionic cores has not been fully recognised. In this work a variety of systems have been explored using a range of exchange-correlation functionals commonly used to explore cluster species, to test the extent of d-electron delocalisation under favourable conditions. Early transition metals have been shown to readily delocalise their valence d-electrons for superatomic shell closing, with higher period atoms showing a greater tendency for delocalisation. Our findings also provide the framework for the design of superatomic systems with large numbers of electrons being contributed from a single atom.
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Affiliation(s)
- J T A Gilmour
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, P.O. Box 600, Wellington, New Zealand
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Gilmour JTA, Gaston N. 5-Fold symmetry in superatomic scandium clusters: exploiting favourable orbital overlap to sequester spin. Phys Chem Chem Phys 2020; 22:4051-4058. [PMID: 32025668 DOI: 10.1039/c9cp05933d] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The geometries and electronic structures of icosahedral A13C (A = Sc, Y; C = 0, ±1, ±2) clusters have been determined at a range of multiplicities at each cluster charge, using density functional theory methods. These clusters demonstrate a complex electronic structure which provides insight into the anomalously high magnetic moment of icosahedral group 3 clusters and further contextualises the role of transition metals and d-electrons within the superatomic model. Embedded deeply within the density of states for these clusters are typical superatom orbitals which are populated up to the 2S level. Above the 2S-state there are three states of apparent F symmetry, which are preferentially singly occupied, followed by an abundance of approximately degenerate P-, G-, D- and F-states at the Fermi energy, which are at most singly occupied. In spite of apparent angular symmetry and a nodal structure reminiscent of superatomic orbitals these states are actually formed from preferential overlap of the valence d-orbitals of the cluster atoms. This analysis was further contextualised through analysis of the Sc19 cluster, which shows a similar construction of Kohn-Sham states, but with the breaking of 5-fold symmetry along one of its Cartesian axes. Finally, this work clearly demonstrates the ability of d-electrons to give rise to superatomic orbitals is not just constrained by atomic species but also by the local environment of the atoms.
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Affiliation(s)
- J T A Gilmour
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, The Department of Physics, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
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Gilmour JTA, Gaston N. On the influence of exact exchange on transition metal superatoms. Phys Chem Chem Phys 2020; 22:772-780. [PMID: 31833486 DOI: 10.1039/c9cp04229f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The electronic structure of A7C (A = Hg, Pd, V, Cr, Mn, Fe, Ni, Cu; C = 0, ±1, ±2) clusters has been determined using density functional theory methods. The A7C (A = Hg, Pd, Cr, Cu; C = 0, ±1, ±2) clusters all conform to the existing superatomic model, with a sufficiently stabilised local structure to prevent perturbation upon the introduction of exact exchange to the exchange correlation functional. For the A7C (A = Mn, Fe, Ni; C = 0, ±1, ±2) clusters the incorporation of exact exchange separates the atomic s- and d-electrons, leading to a net increase in the number of superatomic electrons. Conversely the incorporation of exact exchange into the exchange correlation functional decreases the number of superatomic electrons for the V7C (C = 0, ±1, ±2) clusters, owing to the radial extension of the d-orbitals influencing their ability to contribute into superatomic shells.
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Affiliation(s)
- J T A Gilmour
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, The Department of Physics, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
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Lozano T, Rankin RB. Size, Composition, and Support-Doping Effects on Oxygen Reduction Activity of Platinum-Alloy and on Non-platinum Metal-Decorated-Graphene Nanocatalysts. Front Chem 2019; 7:610. [PMID: 31608270 PMCID: PMC6761360 DOI: 10.3389/fchem.2019.00610] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 08/20/2019] [Indexed: 11/13/2022] Open
Abstract
Recent investigations reported in the open literature concerning the functionalization of graphene as a support material for transition metal nanoparticle catalysts have examined isolated systems for their potential Oxygen Reduction Reaction (ORR) activity. In this work we present results which characterize the ability to use functionalized graphene (via dopants B, N) to upshift and downshift the adsorption energy of mono-atomic oxygen, O* (the ORR activity descriptor on ORR Volcano Plots), for various compositions of 4-atom, 7-atom, and 19-atom sub-nanometer binary alloy/intermetallic transition metal nanoparticle catalysts on graphene (TMNP-MDG). Our results show several important and interesting features: (1) that the combination of geometric and electronic effects makes development of simple linear mixing rules for size/composition difficult; (2) that the transition from 4- to 7- to 19-atom TMNP on MDG has pronounced effects on ORR activity for all compositions; (3) that the use of B and N as dopants to modulate the graphene-TMNP electronic structure interaction can cause shifts in the oxygen adsorption energy of 0.5 eV or more; (4) that it might be possible to make specific doped-graphene-NixCuy TMNP systems which fall close to the Volcano Peak for ORR. Our results point to systems which should be investigated experimentally and may improve the viability of future fuel cell or other ORR applications, and provide new paths for future investigations of more detail for TMNP-MDG screening.
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Affiliation(s)
- Tamara Lozano
- Department of Chemical Engineering, Villanova University, Villanova, PA, United States
| | - Rees B Rankin
- Department of Chemical Engineering, Villanova University, Villanova, PA, United States
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