Subscriber access provided by University of South Dakota
Communication
Chemical Pressure-induced Anion Order-disorder Transition in LnHO Enabled by Hydride Size Flexibility Hiroki Yamashita, Thibault Broux, Yoji Kobayashi, Fumitaka Takeiri, Hiroki Ubukata, Tong Zhu, Michael A. Hayward, Kotaro Fujii, Masatomo Yashima, Kazuki Shitara, Akihide Kuwabara, Taito Murakami, and Hiroshi Kageyama J. Am. Chem. Soc., Just Accepted Manuscript • DOI: 10.1021/jacs.8b06187 • Publication Date (Web): 20 Aug 2018 Downloaded from http://pubs.acs.org on August 20, 2018
Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.
Page 1 of 5 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Journal of the American Chemical Society
Chemical Pressure-induced Anion Order-disorder Transition in LnHO Enabled by Hydride Size Flexibility. Hiroki Yamashita,‡a Thibault Broux,‡a Yoji Kobayashi,a Fumitaka Takeiri,a Hiroki Ubukata,a Tong Zhu,b Michael A. Hayward,b Kotaro Fujii,c Masatomo Yashima,c Kazuki Shitara,d Akihide Kuwabara,e Taito Murakami,a and Hiroshi Kageyama*a a
Graduate School of Engineering, Kyoto University, Kyoto 615-8510 Japan Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QR, UK c Department of Chemistry, School of Science, Tokyo Institute of Technology, Tokyo 152-8551, Japan b
d e
Department of Composite Materials Processing, Osaka University, Ibaraki, Osaka, 567-0047, Japan Nanostructures Research Laboratory, Japan Fine Ceramics Center, Nagoya, 456-8587, Japan
Supporting Information Placeholder ABSTRACT: While cation order-disorder transitions have been achieved in a wide range of materials and provide crucial effects in various physical and chemical properties, anion analogues are scarce. Here we have expanded the number of known lanthanide oxyhydrides LnHO (Ln = La, Ce, Pr, Nd) to include Ln = Sm, Gd, Tb, Dy, Ho and Er, which has allowed the observation of an anion order-disorder transition from the anion-ordered fluorite structure (4/) for larger Ln3+ ions (La – Nd) to a disordered arrangement (3) for smaller Ln3+ (Sm – Er). Structural analysis reveals that with the increase of Ln3+ radius (application of negative chemical pressure), the oxide anion in the disordered phase becomes too under-bonded, which drives a change to an anion-ordered structure, with smaller OLn4 and larger HLn4 tetrahedra, demonstrating that the size flexibility of hydride anions drives this transition. Such anion ordering control is crucial regarding applications that involve hydride diffusion such catalysis and electrochemical solid devices.
The presence or absence of cation order in complex oxides can have a decisive impact on their chemical and physical properties.1,2 In many cases, cation order can be attained by employing combinations of cations with distinct sizes, formal charges, and electronegativity. Thus by controlling these parameters cation order or disorder can be induced (i.e., order-disorder transitions controlled), which are important not only to achieve desired or improved properties, but also to understand the origins behind observed phenomena. There are a number of such examples: the A-site disordered perovskite (Ln0.5Ba0.5)MnO3 (Ln: lanthanide) exhibits charge/orbital order at low temperatures. However, when the A-site is ordered (i.e., LnBaMn2O6 accessible via topochemical oxidation of LnBaMn2O5), the charge/orbital ordering temperature exceeds room temperature, with an enhanced magnetoresistivity.3,4 Similarly, the ionic conductivity of cation-ordered GdBaMn2O6−δ is greater by an order of magnitude relative to the disordered counterpart (Gd0.5Ba0.5)MnO3–δ.5 Other cation orderdisorder transitions can be found in the quadruple perovskite LnMn3V4O12 induced by chemical pressure (i.e., Ln-site substitution),6 Pb(Sc1/2M1/2)O3 (M = Nb, Ta) induced by heat treatment,7 LiGaO2 induced by external pressure (wurtzite to rock salt),8 and ordered LiMnO2 obtained by ion exchange with ordered NaMnO2.9 Mixed-anion compounds, with several anionic species present in a single material,10 can also form anion-ordered structures (e.g., Sr3AlO4F11 and Sr2CoO3Cl12) and anion-disordered ones (e.g., ASrNb2O6F (A = Li, Na, and Rb)13 and Na3V2(PO4)2F3–xOx14). However, unlike the cation case, examples of ‘controlling’ anion
order and disorder (i.e., inducing anion order-disorder transitions) are scarce, aside from anion vacancy order-disorder transitions,15,16 and therefore constitute an important challenge. Oxyhydrides have attracted great deal of attention in recent years.17 Novel properties observed in the oxyhydrides are associated with the unique features of the hydride anion, such as its lability leading to topochemical anion-exchange reactions18,19 and the lack of p orbitals in its valence shell leading to dimensional reduction in Srn+1VnO2n+1Hn (n = 1, 2, ∞).20 Another interesting feature of hydride lies in its size flexibility, indeed the ionic radius of H– in binary metal hydrides varies greatly from 1.27 to 1.52 Å,21 possibly reflecting the small number of electrons in the H– ion, as well as its soft and polarizable nature. Our recent study of SrVO2H at pressures up to 50 GPa explicitly shows the extraordinary compressibility of the hydride anion, with the V-H bond twice as compressible as the V-O bond.22 In this work, we demonstrate that the ‘size flexibility’ of H– can be used to induce an anion order-disorder transition in the LnHO series, where the Ln3+ cations act as chemical pressure. We also present results indicating that these oxyhydrides can serve as supports for highly active NH3 synthesis catalysts.
Figure 1. Structures of LnHO and the corresponding anioncentered environment for (a) the ordered case (4/) with Ln = La – Nd and (b) the anion-disordered case (3) with Ln = Sm – Er. It is reported that LaHO,23 CeHO,24 PrHO24 and NdHO24 crystallize in an anion-ordered fluorite-type structure (4/) that contains three independent lanthanide sites, all in eightfold (H × 4, O × 4) and nearly cubic environments (Figure 1a). Following
ACS Paragon Plus Environment
Journal of the American Chemical Society 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Ref. 24, synthesis of LnHO with other lanthanide (Ln = Sm, Gd, Tb, Dy, Ho and Er) has been carried out. Prior to the anion substitution reaction Ln2O3 was heated at 900 °C overnight to remove adsorbed water and carbonates. In a nitrogen-filled dry glove box Ln2O3 and a three-molar excess of CaH2 were thoroughly mixed together and pelletized. The pellet was placed in an evacuated quartz tube at pressures below 2 × 10–4 MPa and then heated at 650 °C for 20 h. The so-obtained powders were then washed with saturated NH4Cl/methanol remove CaH2 and CaO. Synchrotron X-ray powder diffraction (SXRD) patterns were subsequently collected at room temperature using a camera with an imaging plate as a detector on instrument I11 and a λ = 0.82538 Å wavelength at the Diamond Light Source (UK). As shown in Figure 2, SXRD patterns obtained from LnHO (Ln = Sm, Gd, Tb, Dy, Ho, Er) can be indexed on the basis of a fluorite-type structure, with diffraction peaks shifted to higher angles as the ionic radius of the Ln3+ cation decreases. No traces of rare earth oxide hydroxide were found.25 In the case of Sm additional reflections observed in the data are ascribed to overreacted lanthanide hydride (LnHx). Compounds with Ln = Ho, Dy and Sm contain two phases with identical symmetry and very close cell parameters, with differences of less than 0.002 Å, probably induced by slight anionic composition variation. The synthesis of LnHO with Ln = Eu, Tm, Yb and Lu was unsuccessful, which is ascribed for Eu to undesired reduction (EuH2 was formed), and for the other lanthanides, to a size mismatch preventing the adoption of fluorite-type structures.
Figure 2. SXRD patterns for the anion-disordered phase (3) for Ln = Sm – Er. The low-angle region focus (10 – 11°) emphasizes the absence of superstructure peak associated with the anion ordering. A simulated pattern of the anion ordered NdHO24 is also given for comparison. Based on previous structural studies regarding LnHO with Ln = La to Nd,23,24 the signature of the H–/O2– order is mainly inferred by the presence of a superstructure peak around d = 4.5 – 4.6 Å–1 (which here corresponds to 2θ = 10.5°). As depicted in the low angle enlarged region in the Figure 2, this reflection is absent for all the compounds with Ln3+ cations smaller than Pr, indicating that they adopt anion-disordered structures, analogous to LaFO, with the 3 space group (see Figure 1b).25 Accordingly, Rietveld refinements of SXRD data from the newly prepared samples were carried out assuming anion-disordered models (3) for from SmHO to ErHO, where hydride anions were neglected. All refinements successfully converged (see Supplementary Information for details). Although the presence of hydride has been directly probed only for HoHO by the means of neutron powder diffraction (Figure S1), the charge neutrality condition and oxygen occupancy factor of ~0.5 for the anion-disordered phases strongly suggest the
successful formation of LnHO for all the lanthanides. In addition, the normalized cell volume of our new samples, along with LaHO23 and NdHO,24 nicely shows a linear evolution as a function of lanthanide ionic radius,26 even across the phase boundary (Figure 3a). This not only provides a strong validation of the LnHO composition, but also means that the size of the lanthanide is responsible, more than anything else (e.g., magnetic moment or electronegativity), for the change of the (normalized) unit cell volume. The case presented here provides an ideal situation when one can elucidate the origin of the anion orderdisorder transition in LnHO in terms of the size of the Ln3+ cations, or chemical pressure. Here, chemical pressure refers to a virtual pressure induced by an isovalent substitution, a concept that is often used to describe and tune the properties of solids.27,28
Figure 3. (a) The unit cell volume evolution of LnHO as a function of the Shannon radius of the Ln3+ cation (eight coordination), where, for comparison, the normalized value is given to the anion-ordered tetrahedral phase (Ln = La – Nd).23,24 The tetrahedral cell is related to the cubic cell by √2a × √2a × c (Vtetra ≈ 2Vcubic). (b) Deviation from the ideal valence ∆AV/AV for O2–, obtained from (squares) the refined structural model and from (triangles) the ‘hypothetical’ anion-disordered phase (Ln = La – Nd). (c) Anion-centered tetrahedral volume around H–/O2– (black) for the anion-disordered phase and H– (blue) and O2– (red) for the ordered phase. Lines are guides for the eye. Bond valence sum (BVS) calculations29 have been performed from the anionic point of view for the entire LnHO series (see Figure S2). Shown in Figure 3b is the deviation of the apparent valence (AV) of oxide anions away from the ideal one (= –2), ∆AV/AV, plotted against Ln3+ radius. Values for the ‘hypothetical’ anion-disordered structure (Ln = La, Ce, Pr and Nd) are also displayed, where the normalized (cubic) lattice parameter was employed using reported tetragonal parameters (Vcubic ~ 1/2Vtetra).23,24 It is seen that ∆AV/AV for ErHO is nearly zero (BVS = 1.97), meaning that the oxide anion is in a suitable environment in the tetrahedral coordination site. With increasing Ln3+ radius the magnitude of ∆AV/AV increases linearly, indicating the oxide anion becomes less and less strongly bonded. We can therefore describe the Ln3+ ions as applying negative chemical pressure to the anion sites as the Ln-O bond length expands with
ACS Paragon Plus Environment
Page 2 of 5
Page 3 of 5 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Journal of the American Chemical Society increasing Ln3+ radius. Importantly but not surprisingly, the linear evolution of ∆AV/AV extends across the ‘hypothetical’ aniondisordered structures of Nd → La (triangles in Figure 3b) with ∆AV/AV exceeding –10% at La, which may be expected to drive a change in structure to increase the oxygen coordination number and/or decrease the Ln-O bond length, as seen for example in the change in structure from Er2O3 to La2O3. However, in the case of LnHO the expansion of the Ln3+ lattice induces a transition to an anion-ordered structure in which the oxide and hydride ions are segregated into two distinct tetrahedral sites within a distorted fluoride framework. Note that the BVS analysis of hydride did not exhibit any remarkable feature (see detail in Supporting Information). Thus, it appears that the anion order for La – Nd occurs so as to let oxygen rest in a more ‘comfortable’ environment (squares in Figure 3b). This mechanism for recovering the oxygen valence in the ordered phase for La – Nd is enabled by the size flexibility of hydride anion, which is evident in Figure 3c in which the tetrahedral volume around the anions is plotted. In the anion-disordered phase, the tetrahedral volume around O2–/H– at 8c (Figure 1a, right) shows a linear evolution, but the presence of two crystallographic anion sites in the anion-ordered phase makes the tetrahedral volume split into a larger site (8i) occupied by H– and a smaller site (8i) occupied by O2– (Figure 1b, right). So far, La2O3 is known to adopt the largest OLn4 tetrahedral volume (6.96 Å3) among Ln-containing oxides.31 Interestingly, the anion-ordered LaHO (BVS = –1.92) exhibits a larger value of 7.49 Å3. An even larger value of 7.70 Å3 (leading to BVS = –1.76) is found in the “hypothetical” anion-disordered LaHO, suggesting that the underbonded nature of oxygen is a driving force of the transition. The reduced OLa4 tetrahedral volume of the anion-ordered LaHO (vs. disordered analogue) is enabled by the hydride size flexibility (i.e., swollen HLa4 volume). DFT calculations also yielded a larger OLa4 volume of 7.09 Å3 for the anion-ordered LaHO than computed volumes of 6.76 Å3 and 6.99 Å3 for A- and C-type La2O3 (see detail in Supporting Information). The present study suggests that H–/O2– order-disorder transitions can be controlled in various manners. For example, the application of external (physical) pressure to ordered LnHO (Ln = La – Nd) may drive a change to a disordered phase. Alternatively, the pressurization of disordered LnHO (Ln = Sm – Er) may drive a change to an ordered phase, where contrary to the present study, the hydride anion becomes smaller in size. Given the increasing number of oxyhydride compounds reported recently,17,30–32 we believe that the anion arrangement in oxyhydrides (and other mixed-anion compounds such as hydride-fluoride) can be tuned widely using the hydride’s size flexibility.
Figure 4. Comparison of catalytic activities of various Rubased catalysts,37 conducted at 400˚C, 5 MPa (gauge pressure), with a feed gas composition of N2:H2:Ar = 22.5:67.5:10. The discovery of a new series of oxyhydrides is also interesting in terms of catalysis. Recently, a number of novel
catalyst supports for the Haber-Bosch synthesis of NH3 have been reported, centering on hydrides and electrides. Examples of novel supports are C12A7:e–,33 LiH,34 BaTiO2.5H0.5,35 together with lanthanides such as Pr2O3.36 We have conducted preliminary NH3 activity tests at 5 MPa on some select Ru/LnHO (Ln = Sm, Gd) samples (Figure 4). Compared to other catalysts such as CsRu/MgO or Ru/BaTiO2.5H0.5,37 the activity of Ru/GdHO is extremely high (168 mmol⋅g–1⋅h–1) and warrants further investigation. Since hydride diffusion in Ru/BaTiO2.5H0.5 has been suggested to give a large impact on the catalytic activity,37 the series of oxyhydrides reported here permits a systematic study of the effects of cation/anion basicity, anion order, and hydride diffusion (possibly linked to anion order-disorder) in the context of a chemical application.
ASSOCIATED CONTENT Supporting Information Experimental details including synthesis methods, materials characterization (magnetic susceptibility measurements, Rietveld refinements) and additional data are given in supporting information. The Supporting Information is available free of charge on the ACS Publications website.
AUTHOR INFORMATION Corresponding Author
[email protected] Author Contributions ‡These authors contributed equally.
ACKNOWLEDGMENT This work was supported by CREST (JPMJCR1421), JSPS KAKENHI (JP17H06439, JP17H06440, JP16H06441, JP15H03849), PRESTO (JPMJPR1441) and, JSPS postdoctoral fellowship (TB). Experiments at the Diamond Light Source were performed as part of the Block Allocation Group award (EE13284).
REFERENCES (1) King, G.; Woodward, P. M. Cation Ordering in Perovskites. J. Mater. Chem. 2010, 20, 5785–5796. (2) Davies, P. K. Cation Ordering in Complex Oxides. Curr. Opin. Solid State Mater. Sci. 1999, 4, 467–471. (3) Millange, F.; Caignaert, V.; Domengès, B.; Raveau, B.; Suard, E. Order−Disorder Phenomena in New LaBaMn2O6–x CMR Perovskites. Crystal and Magnetic Structure. Chem. Mater. 1998, 10, 1974–1983. (4) Nakajima, T.; Kageyama, H.; Yoshizawa, H.; Ueda, Y. Structures and Electromagnetic Properties of New Metal-Ordered Manganites: RBaMn2O6 (R = Y and Rare-Earth Elements). J. Phys. Soc. Jpn. 2002, 71, 2843–2846. (5) Taskin, A. A.; Lavrov, A. N.; Ando, Y. Achieving Fast Oxygen Diffusion in Perovskites by Cation Ordering. Appl. Phys. Lett. 2005, 86, 091910. (6) Shimakawa, Y.; Zhang, S.; Saito, T.; Lufaso, M. W.; Woodward, P. M. Order-Disorder Transition Involving the A-Site Cations in 3+ Ln Mn3V4O12 Perovskites. Inorg. Chem. 2014, 53, 594–599. (7) Stenger, C. G. F.; Burggraaf, A. J. Order–disorder Reactions in the Ferroelectric Perovskites Pb(Sc1/2Nb1/2)O3 and Pb(Sc1/2Ta1/2)O3. I. Kinetics of the Ordering Process. Phys. Status Solidi A 1980, 61, 275–285. (8) Lei, L.; Irifune, T.; Shinmei, T.; Ohfuji, H.; Fang, L. Cation Order–disorder Phase Transitions in LiGaO2: Observation of the Pathways of Ternary Wurtzite under High Pressure. J. Appl. Phys. 2010, 108, 083531. (9) Vitins, G.; West, K. Lithium Intercalation into Layered LiMnO2. J. Electrochem. Soc. 1997, 144, 2587–2592.
ACS Paragon Plus Environment
Journal of the American Chemical Society 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
(10) Kageyama, H.; Hayashi, K.; Maeda, K.; Attfield, J. P.; Hiroi, Z.; Rondinelli, J. M.; Poeppelmeier, K. R. Expanding Frontiers in Materials Chemistry and Physics with Multiple Anions. Nat. Commun. 2018, 9, 772. (11) Prodjosantoso, A. K.; Kennedy, B. J.; Vogt, T.; Woodward, P. M. Cation and Anion Ordering in the Layered Oxyfluorides Sr3–xAxAlO4F (A = Ba, Ca). J. Solid State Chem. 2003, 172, 89–94. (12) Loureiro, S. M.; Felser, C.; Huang, Q.; Cava, R. J. Refinement of the Crystal Structures of Strontium Cobalt Oxychlorides by Neutron Powder Diffraction. Chem. Mater. 2000, 12, 3181–3185. (13) Choy, J.-H.; Kim, J.-Y.; Kim, S.-J.; Sohn, J.-S.; Han, O. H. New Dion−Jacobson-Type Layered Perovskite Oxyfluorides, ASrNb2O6F (A = Li, Na, and Rb). Chem. Mater. 2001, 13, 906–912. (14) Broux, T.; Bamine, T.; Fauth, F.; Simonelli, L.; Olszewski, W.; Marini, C.; Ménétrier, M.; Carlier, D.; Masquelier, C.; Croguennec, L. Strong Impact of the Oxygen Content in Na3V2(PO4)2F3–yOy (0 ≤ y ≤ 0.5) on Its Structural and Electrochemical Properties. Chem. Mater. 2016, 28, 7683–7692. (15) Broux, T.; Bahout, M.; Hernandez, O.; Tonus, F.; Paofai, S.; Hansen, T.; Greaves, C. Reduction of Sr2MnO4 Investigated by High Temperature in Situ Neutron Powder Diffraction under Hydrogen Flow. Inorg. Chem. 2013, 52, 1009–1017. (16) Seddon, J.; Suard, E.; Hayward, M. A. Topotactic Reduction of YBaCo2O5 and LaBaCo2O5: Square-Planar Co(I) in an Extended Oxide. J. Am. Chem. Soc. 2010, 132, 2802–2810. (17) Kobayashi, Y.; Hernandez, O.; Tassel, C.; Kageyama, H. New Chemistry of Transition Metal Oxyhydrides. Sci. Technol. Adv. Mater. 2017, 18, 905–918. (18) Yajima, T.; Takeiri, F.; Aidzu, K.; Akamatsu, H.; Fujita, K.; Yoshimune, W.; Ohkura, M.; Lei, S.; Gopalan, V.; Tanaka, K.; et al. A Labile Hydride Strategy for the Synthesis of Heavily Nitridized BaTiO3. Nat. Chem. 2015, 7, 1017–1023. (19) Masuda, N.; Kobayashi, Y.; Hernandez, O.; Bataille, T.; Paofai, S.; Suzuki, H.; Ritter, C.; Ichijo, N.; Noda, Y.; Takegoshi, K.; et al. Hydride in BaTiO2.5H0.5: A Labile Ligand in Solid State Chemistry. J. Am. Chem. Soc. 2015, 137, 15315–15321. (20) Denis Romero, F.; Leach, A.; Möller, J. S.; Foronda, F.; Blundell, S. J.; Hayward, M. A. Strontium Vanadium Oxide–Hydrides: “Square-Planar” Two-Electron Phases. Angew. Chem. Int. Ed. 2014, 53, 7556–7559. (21) Libowitz, George G. The Solid-State Chemistry of Binary Metal Hydrides; WA Benjamin, 1965. (22) Yamamoto, T.; Zeng, D.; Kawakami, T.; Arcisauskaite, V.; Yata, K.; Patino, M. A.; Izumo, N.; McGrady, J. E.; Kageyama, H.; Hayward, M. A. The Role of π-Blocking Hydride Ligands in a PressureInduced Insulator-to-Metal Phase Transition in SrVO2H. Nat. Commun. 2017, 8, 1217. (23) Malaman, B.; Brice, J. F. Etude Structurale de l’hydruroOxyde LaHO Par Diffraction Des Rayons X et Par Diffraction Des Neutrons. J. Solid State Chem. 1984, 53, 44–54. (24) Widerøe, M. NdHO, a Novel Oxyhydride. J. Solid State Chem. 2011, 184, 1890–1894. (25) Klein, W.; Klein, H.-A. Lanthanoxyfluorid. Z. Für Anorg. Allg. Chem. 1941, 248, 167–171.
(26) Shannon, R. D. Revised Effective Ionic Radii and Systematic Studies of Interatomic Distances in Halides and Chalcogenides. Acta Crystallogr. A 1976, 32, 751–767. (27) Sánchez-Benítez, J.; Alonso, J. A.; Martínez-Lope, M. J.; de Andrés, A.; Fernández-Díaz, M. T. Enhancement of the Curie Temperature along the Perovskite Series RCu3Mn4O12 Driven by Chemical Pressure of R3+ Cations (R = Rare Earths). Inorg. Chem. 2010, 49, 5679–5685. (28) Marezio, M.; Licci, F.; Gauzzi, A. Chemical Pressure for Optimizing Tc in a given Superconducting System. Phys. C Supercond. 2000, 337, 195–199. (29) Brese, N. E.; O’Keeffe, M. Bond-Valence Parameters for Solids. Acta Crystallogr. B 1991, 47, 192–197. (30) Goto, Y.; Tassel, C.; Noda, Y.; Hernandez, O.; Pickard, C. J.; Green, M. A.; Sakaebe, H.; Taguchi, N.; Uchimoto, Y.; Kobayashi, Y.; et al. Pressure-Stabilized Cubic Perovskite Oxyhydride BaScO2H. Inorg. Chem. 2017, 56, 4840–4845. (31) Tassel, C.; Goto, Y.; Watabe, D.; Tang, Y.; Lu, H.; Kuno, Y.; Takeiri, F.; Yamamoto, T.; Brown, C. M.; Hester, J.; et al. High-Pressure Synthesis of Manganese Oxyhydride with Partial Anion Order. Angew. Chem. 2016, 128, 9819–9822. (32) Tassel, C.; Goto, Y.; Kuno, Y.; Hester, J.; Green, M.; Kobayashi, Y.; Kageyama, H. Direct Synthesis of Chromium Perovskite Oxyhydride with a High Magnetic-Transition Temperature. Angew. Chem. Int. Ed. 2014, 53, 10377–10380. (33) Kitano, M.; Inoue, Y.; Yamazaki, Y.; Hayashi, F.; Kanbara, S.; Matsuishi, S.; Yokoyama, T.; Kim, S.-W.; Hara, M.; Hosono, H. Ammonia Synthesis Using a Stable Electride as an Electron Donor and Reversible Hydrogen Store. Nat. Chem. 2012, 4, 934–940. (34) Wang, P.; Chang, F.; Gao, W.; Guo, J.; Wu, G.; He, T.; Chen, P. Breaking Scaling Relations to Achieve Low-Temperature Ammonia Synthesis through LiH-Mediated Nitrogen Transfer and Hydrogenation. Nat. Chem. 2017, 9, 64–70. (35) Kobayashi, Y.; Tang, Y.; Kageyama, T.; Yamashita, H.; Masuda, N.; Hosokawa, S.; Kageyama, H. Titanium-Based Hydrides as Heterogeneous Catalysts for Ammonia Synthesis. J. Am. Chem. Soc. 2017, 139, 18240–18246. (36) Ogura, Y.; Sato, K.; Miyahara, S.; Kawano, Y.; Toriyama, T.; Yamamoto, T.; Matsumura, S.; Hosokawa, S.; Nagaoka, K. Efficient Ammonia Synthesis over a Ru/La0.5Ce0.5O1.75 Catalyst Pre-Reduced at High Temperature. Chem. Sci. 2018, 9, 2230–2237. (37) Tang Y. et al. Metal-Dependent Support Effects of Oxyhydride-Supported Ru, Fe, Co Catalysts for Ammonia Synthesis. Adv. Ener. Mat. submitted.
ACS Paragon Plus Environment
Page 4 of 5
Page 5 of 5 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Journal of the American Chemical Society
ACS Paragon Plus Environment
5
