Molybdenum chalcogenides: clusters, chains, and extended solids. The approach to bonding in three dimensions

Hughbanks, Timothy; Hoffmann, Roald

doi:10.1021/ja00343a014

Cited by 280 publications

(161 citation statements)

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“…13 Downloaded on 2018-05-12 to IP anisotropic channel character, would not allow filling of a larger part of the vacant sites although the number of them is high in o-Mo 9 Se 11 . 21 On the other hand, in the case of Chevrel compounds, Mo 6 X 8 (X = S, Se), with three-dimensional diffusion channel, 33 it is reported that both Li-and Mg-systems show the similar order capacity comparable with the theoretical capacity 11,12,[17][18][19][20]34,35 deduced from the molecular orbital model, 23 in which extra four electrons per formula unit form closed-shell configuration of bonding orbitals. The threedimensional diffusion channel could work effectively to reduce the energy increase by Coulomb repulsion between the inserted ions.…”

Section: Resultsmentioning

confidence: 75%

“…The early theoretical studies suggested that the all bonding orbitals of Mo 9 -cluster should be fulfilled by electrons as in Mo 9 Se 11 4− under assumption that an oxidation state is -2 for Se. 23,24 Thus, o-Mo 9 Se 11 is obtained only as a metastable phase by topotactic ion-extraction from a stable phase, such as o-Ag 3.6 Mo 9 Se 11 . In the crystal structure of o-Mo 9 Se 11 , the one-dimensional channel extending along the [100]-direction exists ( Fig.…”

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confidence: 99%

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Reversible Electrochemical Insertion/Extraction of Mg and Li Ions for Orthorhombic Mo₉Se₁₁with Cluster Structure

Taniguchi

Yoshino

et al. 2014

J. Electrochem. Soc.

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The reversible electrochemical insertion/extraction of Mg 2+ and Li + into/from a crystalline has been found in orthorhombic Mo 9 Se 11 (o-Mo 9 Se 11 ), the crystal structure of which is composed of molybdenum cluster units. The insertion/extraction reversibility of bivalent ion, Mg 2+ , could be ascribed to improvement of slow diffusion in the host lattice through the delocalization effect of electrons induced by cluster structure as supposed in Chevrel phase. The characteristic of Li/Mg-ion half-cell with o-Mo 9 Se 11 cathode, such as discharge curve and theoretical capacity, are discussed based on the electronic structure. A part of discharge curve in the insertion process of Li + was likely ascribed to the psuedogap structure in the density of state for the electronic band. The reversible capacity of o-Mg x Mo 9 Se 11 was below 40% of the theoretical capacity deduced from the molecular orbital model, whereas over 80% of that was observed in o-Li x Mo 9 Se 11 . The smaller reversible capacity for Mg 2+ could be ascribed to the Coulomb repulsion between bivalent Mg-ions confined in the one-dimensional channel of o-Mo 9 Se 11 , which highly prevents ion-insertion for bivalent Mg-ions compared with that for monovalent Li-ions. We suggest that both delocalized electronic structure and high dimensional ion-channel are necessary to realize reversible cathodes of Mg-ion battery with high capacity. Reversible electrochemical insertion/extraction of cations into/from materials is an important phenomenon from the view point of today's science and technology. In particular, reversible insertion/extraction of Li-ion is applied to secondary battery systems (Li-ion batteries) and has enabled realization of widely used portable devices such as cellular phones and lap-top computers.1-4 In recent years, an effort for developing new energy storage systems, which use ion-insertion mechanism, is being invested also in nonlithium-ion battery systems, such as sodium-ion, 5,6 potassium-ion 7,8 and multivalent-ion batteries. 9-16 Among them, Mg-ion battery is one of the fascinating battery systems due to its possible low cost and safety, which could be realized by rich resource and moderate reactivity of magnesium. [9][10][11][12] However, in most materials, the strong electrostatic interaction between introduced Mg 2+ and host lattice, which is due to bivalence of Mg 2+ , induces the slow solid state diffusion of Mg-ions within the crystal lattice and hampers reversible electrochemical insertion/extraction of Mg 2+ . 9,11,12 At present, the only family of insertion systems, into/from which reversible insertion/extraction of Mg-ions has been rigorously established, is Chevrel phases, Mo 6 X 8 (X = S, Se). These systems have demonstrated reversible insertion/extraction of Mg-ions over 1000 cycles and the capacity over 70 mAh/g, which is higher than those of other transition metal sulphides, as a cathode of Mg-ion battery at ambient temperature. 17,18 The successful performance of Chevrel phases as Mg-insertion materials is suggested...

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Section: Resultsmentioning

confidence: 75%

mentioning

confidence: 99%

Reversible Electrochemical Insertion/Extraction of Mg and Li Ions for Orthorhombic Mo₉Se₁₁with Cluster Structure

Taniguchi

Yoshino

et al. 2014

J. Electrochem. Soc.

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“…In the series of large-cation sulfide Chevrel phases (MMo6S8 where M is a metallic cation), it is generally believed that non-stoichiometry, if any, occurs on the 2(c) sulfur sites along the rhombohedral axis. This issue has been addressed previously, theoretically (Hughbanks & Hoffmann, 1983) and experimentally -powder neutron diffraction showed that partial S-atom substitution by O Sno.854Mo658 atoms can occur (Hinks, Jorgensen & Li, 1983) and this was confirmed by single-crystal characterization (Chang, Tao, Swinnea & Steinfink, 1987). Evidence for missing S atoms on the 2(c) special positions has also been shown for a PbMorS8 single crystal (Marezio, Dernier, Remeika, Corenzwit & Matthias, 1973).…”

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confidence: 73%

Structure of Sn0.854Mo6S8

Lay¹,

Powell²,

Willis³

1992

Acta Crystallogr C

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TOUBOUL, LOKAJ, TESSIER, KETTMAN AND VRABEL 1179 layer (Fig. 2) but the formula has changed because 0(3) atoms also belong to the coordination sphere of Bi; the formula of the layer of the corner-sharing VO6 octahedra is thus VO2.75°5-.According to Zhou (1988), in the Bi2VOs.5 structure there are no Bi2022÷ layers and this compound cannot be included in the Aurivillius family of oxides. The structure of BizVO55 contains alternating ~,12,-,z75 TM c~o.5+ layers formed by very irregular cornerVOz75 layers of cornersharing BiO4 tetrahedra and o.5-sharing distorted VO6 octahedra. (Received 11 June 1991; accepted 9 December 1991) Abstract. Molybdenum tin sulfide, Sn0 854Mo658, Mr =933.5, trigonal, R3, an= 6.5100i10) A, an= 89.47 (2) °, VR = 275.86 (7) ,~3, Z = 1, Ox = 5.619 Mg m -3, A(Mo Ka) = 0.71073/~, # = 9.777 mm-i, F(000) = 422.70, T = 295 K, R = 0.0401 for 517 observed reflections. The title compound is isostructural to SnMO6SB, but displays a cation nonstoichiometry. References

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“…Band structure scheme of chalcogenide clusters. Adapted from [72,73]. Reprinted with permission from [72].…”

Section: Transition Metal Chalcogenidesmentioning

confidence: 99%

What Can We Learn in Electrocatalysis, from Nanoparticulated Precious and/or Non-Precious Catalytic Centers Interacting with Their Support?

2016

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This review is devoted to discussing the state of the art in the relevant aspects of the synthesis of novel precious and non-precious electrocatalysts. It covers the production of Pt-and Pd-based electrocatalysts synthesized by the carbonyl chemical route, the synthesis description for the preparation of the most catalytically active transition metal chalcogenides, then the employment of free-surfactants synthesis routes to produce non-precious electrocatalysts. A compilation of the best precious electrocatalysts to perform the hydrogen oxidation reaction (HOR) is described; a section is devoted to the synthesis and electrocatalytic evaluation of non-precious materials which can be used to perform the HOR in alkaline medium. Apropos the oxygen reduction reaction (ORR), the synthesis and modification of the supports is also discussed as well, aiming at describing the state of the art to improve kinetics of low temperature fuel cell reactions via the hybridization process of the catalytic center with a variety of carbon-based, and ceramic-carbon supports. Last, but not least, the review covers the experimental half-cells results in a micro-fuel cell platform obtained in our laboratory, and by other workers, analyzing the history of the first micro-fuel cell systems and their tailoring throughout the time bestowing to the design and operating conditions.

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Molybdenum chalcogenides: clusters, chains, and extended solids. The approach to bonding in three dimensions

Cited by 280 publications

References 2 publications

Reversible Electrochemical Insertion/Extraction of Mg and Li Ions for Orthorhombic Mo₉Se₁₁with Cluster Structure

Reversible Electrochemical Insertion/Extraction of Mg and Li Ions for Orthorhombic Mo₉Se₁₁with Cluster Structure

Structure of Sn0.854Mo6S8

What Can We Learn in Electrocatalysis, from Nanoparticulated Precious and/or Non-Precious Catalytic Centers Interacting with Their Support?

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Molybdenum chalcogenides: clusters, chains, and extended solids. The approach to bonding in three dimensions

Cited by 280 publications

References 2 publications

Reversible Electrochemical Insertion/Extraction of Mg and Li Ions for Orthorhombic Mo9Se11with Cluster Structure

Reversible Electrochemical Insertion/Extraction of Mg and Li Ions for Orthorhombic Mo9Se11with Cluster Structure

Structure of Sn0.854Mo6S8

What Can We Learn in Electrocatalysis, from Nanoparticulated Precious and/or Non-Precious Catalytic Centers Interacting with Their Support?

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Reversible Electrochemical Insertion/Extraction of Mg and Li Ions for Orthorhombic Mo₉Se₁₁with Cluster Structure

Reversible Electrochemical Insertion/Extraction of Mg and Li Ions for Orthorhombic Mo₉Se₁₁with Cluster Structure