1
|
Liang Z, Batuk M, Orlandi F, Manuel P, Hadermann J, Hayward MA. Competition between Anion-Deficient Oxide and Oxyhydride Phases during the Topochemical Reduction of LaSrCoRuO 6. Inorg Chem 2024; 63:12910-12919. [PMID: 38940638 PMCID: PMC11256754 DOI: 10.1021/acs.inorgchem.4c01568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 06/13/2024] [Accepted: 06/14/2024] [Indexed: 06/29/2024]
Abstract
Binary metal hydrides can act as low-temperature reducing agents for complex oxides in the solid state, facilitating the synthesis of anion-deficient oxide or oxyhydride phases. The reaction of LaSrCoRuO6, with CaH2 in a sealed tube yields the face-centered cubic phase LaSrCoRuO3.2H1.9. The reaction with LiH under similar conditions converts LaSrCoRuO6 to a mixture of tetragonal LaSrCoRuO4.8H1.2 and cubic LaSrCoRuO3.3H2.13. The formation of the LaSrCoRuOxHy oxyhydride phases proceeds directly from the parent oxide, with no evidence for anion-deficient LaSrCoRuO6-x intermediates, in contrast with many other topochemically synthesized transition-metal oxyhydrides. However, the reaction between LaSrCoRuO6 and LiH under flowing argon yields a mixture of LaSrCoRuO5 and the infinite layer phase LaSrCoRuO4. The change to all-oxide products when reactions are performed under flowing argon is attributed to the lower hydrogen partial pressure under these conditions. The implications for the reaction mechanism of these topochemical transformations is discussed along with the role of the hydrogen partial pressure in oxyhydride synthesis. Magnetization measurements indicate the LaSrCoRuOxHy phases exhibit local moments on Co and Ru centers, which are coupled antiferromagnetically. In contrast, LaSrCoRuO4 exhibits ferromagnetic behavior with a Curie temperature above 350 K, which can be rationalized on the basis of superexchange coupling between the Co1+ and Ru2+ centers.
Collapse
Affiliation(s)
- Zhilin Liang
- Department
of Chemistry, University of Oxford, Inorganic
Chemistry Laboratory, South Parks Road, Oxford OX1 3QR, U.K.
| | - Maria Batuk
- EMAT, University of Antwerp, Groenenborgerlaan 171, Antwerp B-2020, Belgium
| | - Fabio Orlandi
- ISIS
Facility, Rutherford Appleton Laboratory, Chilton ,Oxon OX11 0QX, U.K.
| | - Pascal Manuel
- ISIS
Facility, Rutherford Appleton Laboratory, Chilton ,Oxon OX11 0QX, U.K.
| | - Joke Hadermann
- EMAT, University of Antwerp, Groenenborgerlaan 171, Antwerp B-2020, Belgium
| | - Michael A. Hayward
- Department
of Chemistry, University of Oxford, Inorganic
Chemistry Laboratory, South Parks Road, Oxford OX1 3QR, U.K.
| |
Collapse
|
2
|
He Y, Li Y, Lei M, Polo-Garzon F, Perez-Aguilar J, Bare SR, Formo E, Kim H, Daemen L, Cheng Y, Hong K, Chi M, Jiang DE, Wu Z. Significant Roles of Surface Hydrides in Enhancing the Performance of Cu/BaTiO 2.8 H 0.2 Catalyst for CO 2 Hydrogenation to Methanol. Angew Chem Int Ed Engl 2024; 63:e202313389. [PMID: 37906130 DOI: 10.1002/anie.202313389] [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: 09/08/2023] [Revised: 10/24/2023] [Accepted: 10/31/2023] [Indexed: 11/02/2023]
Abstract
Tuning the anionic site of catalyst supports can impact reaction pathways by creating active sites on the support or influencing metal-support interactions when using supported metal nanoparticles. This study focuses on CO2 hydrogenation over supported Cu nanoparticles, revealing a 3-fold increase in methanol yield when replacing oxygen anions with hydrides in the perovskite support (Cu/BaTiO2.8 H0.2 yields ~146 mg/h/gCu vs. Cu/BaTiO3 yields ~50 mg/h/gCu). The contrast suggests that significant roles are played by the support hydrides in the reaction. Temperature programmed reaction and isotopic labelling studies indicate that BaTiO2.8 H0.2 surface hydride species follow a Mars van Krevelen mechanism in CO2 hydrogenation, promoting methanol production. High-pressure steady-state isotopic transient kinetic analysis (SSITKA) studies suggest that Cu/BaTiO2.8 H0.2 possesses both a higher density and more active and selective sites for methanol production compared to Cu/BaTiO3 . An operando high-pressure diffuse reflectance infrared spectroscopy (DRIFTS)-SSITKA study shows that formate species are the major surface intermediates over both catalysts, and the subsequent hydrogenation steps of formate are likely rate-limiting. However, the catalytic reactivity of Cu/BaTiO2.8 H0.2 towards the formate species is much higher than Cu/BaTiO3 , likely due to the altered electronic structure of interface Cu sites by the hydrides in the support as validated by density functional theory (DFT) calculations.
Collapse
Affiliation(s)
- Yang He
- Chemical Sciences Division and Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN-37831, USA
| | - Yuanyuan Li
- Chemical Sciences Division and Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN-37831, USA
| | - Ming Lei
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN-37235, USA
| | - Felipe Polo-Garzon
- Chemical Sciences Division and Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN-37831, USA
| | - Jorge Perez-Aguilar
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA-94025, USA
| | - Simon R Bare
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA-94025, USA
| | - Eric Formo
- Georgia Electron Microscopy, University of Georgia, Athens, GA-30602, USA
| | - Hwangsun Kim
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN-37831, USA
| | - Luke Daemen
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN-37831, USA
| | - Yongqiang Cheng
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN-37831, USA
| | - Kunlun Hong
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN-37831, USA
| | - Miaofang Chi
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN-37831, USA
| | - De-En Jiang
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN-37235, USA
| | - Zili Wu
- Chemical Sciences Division and Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN-37831, USA
| |
Collapse
|
3
|
Aleksis R, Pell AJ. Separation of quadrupolar and paramagnetic shift interactions in high-resolution nuclear magnetic resonance of spinning powders. J Chem Phys 2021; 155:094202. [PMID: 34496580 DOI: 10.1063/5.0061611] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Separation and correlation of the shift anisotropy and the first-order quadrupolar interaction of spin I = 1 nuclei under magic-angle spinning (MAS) are achieved by the phase-adjusted spinning sideband (PASS) nuclear magnetic resonance (NMR) experiment. Compared to methods for static samples, this approach has the benefit of higher sensitivity and resolution. Moreover, the PASS experiment has the advantage over previous MAS sequences in the ability to completely separate the shift anisotropy and first-order quadrupolar interactions. However, the main drawback of the pulse sequence is the lower excitation bandwidth. The sequence is comprehensively evaluated using theoretical calculations and numerical simulations and applied experimentally to the 2H NMR of a range of paramagnetic systems: deuterated nickel(II) acetate tetrahydrate, deuterated copper(II) chloride dihydrate, and two forms of deuterated oxyhydride ion conductor BaTiO3-xHy. Our results show that despite the issue with broadband excitation, the extracted shift and quadrupolar interaction tensors and the Euler angles relating the two tensors match well with the NMR parameters obtained with static NMR methods. Therefore, the new application of the PASS experiment is an excellent addition to the arsenal of NMR experiments for 2H and potentially 14N in paramagnetic solids.
Collapse
Affiliation(s)
- Rihards Aleksis
- Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Andrew J Pell
- Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden
| |
Collapse
|
4
|
Abstract
We investigated the nitridation of reduced BaTiO3, BaTiO2.60H0.08, corresponding to an oxyhydride with a large concentration of O defects (>10%). The material is readily nitrided under flowing N2 gas at temperatures between 400 and 450 °C to yield oxynitrides BaTiO2.6Nx (x = 0.2−0.22) with a slightly tetragonally distorted perovskite structure, a ≈ 4.01 and c ≈ 4.02 Å, and Ti partially remaining in the oxidation state III. The tetragonal structure was confirmed from Raman spectroscopy. 14N MAS NMR spectroscopy shows a single resonance at 270 ppm, which is typical for perovskite transition metal oxynitrides. However, largely different signal intensity for materials with very similar N content suggests N/O/vacancy ordering when prolonging nitridation times to hours. Diffuse reflectance UV-VIS spectroscopy shows a reduction of the intrinsic band gap to 2.4–2.45 eV compared to BaTiO3 (~3.2 eV). Mott-Schottky measurements confirm n-type conductivity and reveal a slight negative shift of the conduction band edge from –0.59 V (BaTiO3) to ~–0.65 eV.
Collapse
|
5
|
Carvalho JP, Pell AJ. Frequency-swept adiabatic pulses for broadband solid-state MAS NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2021; 324:106911. [PMID: 33482528 DOI: 10.1016/j.jmr.2020.106911] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/17/2020] [Accepted: 12/25/2020] [Indexed: 06/12/2023]
Abstract
We present a complete description of frequency-swept adiabatic pulses applied to isolated spin-1/2 nuclei with a shift anisotropy in solid materials under magic-angle spinning. Our theoretical framework unifies the existing descriptions of adiabatic pulses in the high-power regime, where the radiofrequency (RF) amplitude is greater than twice the spinning frequency, and the low-power regime, where the RF power is less than the spinning frequency, and so links the short high-powered adiabatic pulse (SHAP) and single-sideband-selective adiabatic pulses (S3AP) schemes used in paramagnetic solid-state NMR. We also identify a hitherto unidentified third regime intermediate between the low- and high-power regimes, and separated from them by rotary resonance conditions. We show that the prevailing benchmark of inversion performance based on (super) adiabatic factors is only applicable in the high- and intermediate-power regimes, but fails to account both for the poor performance at rotary resonance, and the impressive inversion seen in the low-power regime. For low-power pulses, which are non-adiabatic according to this definition of (super) adiabaticity, the effective Floquet Hamiltonian in the jolting frame reveals "hidden" (super) adiabaticity. The theory is demonstrated using a combination of simulation and experiment, and is used to refine the practical recommendations for the experimentalist who wishes to use these pulses.
Collapse
Affiliation(s)
- José P Carvalho
- Materials and Environmental Chemistry, Stockholm University, Svänte Arrhenius väg 16 C 106 91, Stockholm, Sweden
| | - Andrew J Pell
- Materials and Environmental Chemistry, Stockholm University, Svänte Arrhenius väg 16 C 106 91, Stockholm, Sweden; Centre de RMN Trés Hauts Champs de Lyon (FRE 2034 - CNRS, ENS Lyon, UCB Lyon 1), Université de Lyon, 5 rue de la Doua, 69100 Villeurbanne, France.
| |
Collapse
|
6
|
Tao Y, Wang P, Liang C, Yang N, Huang D, Chen H, Luo Y. Tailoring Oxygen Vacancies in CoMoO
4
for Superior Lithium Storage. ChemElectroChem 2020. [DOI: 10.1002/celc.202001379] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Yuanxue Tao
- College of Science Huazhong Agricultural University Wuhan 430070 PR China
| | - Pei Wang
- College of Science Huazhong Agricultural University Wuhan 430070 PR China
| | - Chennan Liang
- College of Science Huazhong Agricultural University Wuhan 430070 PR China
| | - Nan Yang
- College of Science Huazhong Agricultural University Wuhan 430070 PR China
| | - Dekang Huang
- College of Science Huazhong Agricultural University Wuhan 430070 PR China
| | - Hao Chen
- College of Science Huazhong Agricultural University Wuhan 430070 PR China
| | - Yanzhu Luo
- College of Science Huazhong Agricultural University Wuhan 430070 PR China
| |
Collapse
|
7
|
Guo H, Jaworski A, Ma Z, Slabon A, Bacsik Z, Nedumkandathil R, Häussermann U. Trapping of different stages of BaTiO 3 reduction with LiH. RSC Adv 2020; 10:35356-35365. [PMID: 35515653 PMCID: PMC9056924 DOI: 10.1039/d0ra07276a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 09/15/2020] [Indexed: 11/21/2022] Open
Abstract
We investigated the hydride reduction of tetragonal BaTiO3 using LiH. The reactions employed molar H : BaTiO3 ratios of 1.2, 3, and 10 and variable temperatures up to 700 °C. The air-stable reduced products were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy, thermogravimetric analysis (TGA), X-ray fluorescence (XRF), and 1H magic-angle spinning (MAS) NMR spectroscopy. Effective reduction, as indicated by the formation of dark blue to black colored, cubic-phased, products was observed at temperatures as low as 300 °C. The product obtained at 300 °C corresponded to oxyhydride BaTiO∼2.9H∼0.1, whereas reduction at higher temperatures resulted in simultaneous O defect formation, BaTiO2.9-x H0.1□ x , and eventually - at temperatures above 450 °C - to samples void of hydridic H. Concomitantly, the particles of samples reduced at high temperatures (500-600 °C) display substantial surface alteration, which is interpreted as the formation of a TiO x (OH) y shell, and sintering. Diffuse reflectance UV-VIS spectroscopy shows broad absorption in the VIS-NIR region, which is indicative of the presence of n-type free charge carriers. The size of the intrinsic band gap (∼3.2 eV) appears only slightly altered. Mott-Schottky measurements confirm the n-type conductivity and reveal shifts of the conduction band edge in the LiH reduced samples. Thus LiH appears as a versatile reagent to produce various distinct forms of reduced BaTiO3 with tailored electronic properties.
Collapse
Affiliation(s)
- Hua Guo
- Department of Materials and Environmental Chemistry, Stockholm University SE-10691 Stockholm Sweden
| | - Aleksander Jaworski
- Department of Materials and Environmental Chemistry, Stockholm University SE-10691 Stockholm Sweden
| | - Zili Ma
- Department of Materials and Environmental Chemistry, Stockholm University SE-10691 Stockholm Sweden .,Institute of Inorganic Chemistry, RWTH Aachen University Landoltweg 1 DE-52074 Aachen Germany
| | - Adam Slabon
- Department of Materials and Environmental Chemistry, Stockholm University SE-10691 Stockholm Sweden
| | - Zoltan Bacsik
- Department of Materials and Environmental Chemistry, Stockholm University SE-10691 Stockholm Sweden
| | - Reji Nedumkandathil
- Department of Materials and Environmental Chemistry, Stockholm University SE-10691 Stockholm Sweden
| | - Ulrich Häussermann
- Department of Materials and Environmental Chemistry, Stockholm University SE-10691 Stockholm Sweden
| |
Collapse
|
8
|
Aleksis R, Carvalho JP, Jaworski A, Pell AJ. Artefact-free broadband 2D NMR for separation of quadrupolar and paramagnetic shift interactions. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2019; 101:51-62. [PMID: 31121358 DOI: 10.1016/j.ssnmr.2019.05.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 04/30/2019] [Accepted: 05/01/2019] [Indexed: 06/09/2023]
Abstract
Two new two-dimensional, broadband, solid-state NMR experiments for separating and correlating the quadrupolar and shift interactions of spin I=1 nuclei in paramagnetic systems are proposed. The new pulse sequences incorporate the short, high-power adiabatic pulses (SHAPs) into the shifting d-echo experiment of Walder et al. [J. Chem. Phys., 142, 014201 (2015)], in two different ways, giving double and quadruple adiabatic shifting d-echo sequences. These new experiments have the advantage over previous methods of both suppressing spectral artefacts due to pulse imperfections, and exhibiting a broader excitation bandwidth. Both experiments are analysed with theoretical calculations and simulations, and are applied experimentally to the 2H NMR of deuterated CuCl2 ⋅2H2O, and two deuterated samples of the ion conductor oxyhydride BaTiO3-xHy prepared using two different methods. For the CuCl2 ⋅2H2O sample, both new methods obtain very high-quality spectra from which the parameters describing the shift and quadrupolar interaction tensors, and their relative orientation, were extracted. The two BaTiO3-xHy samples exhibited different local hydride environments with different tensor parameters. The 2H spectra of these oxyhydrides exhibit inhomogeneous broadening of the 2H shifts, and so whilst the quadrupolar interaction parameters were easily extracted, the measurement of the shift parameters was more complex. However, effective shift parameters were extracted, which combine the effects of both the paramagnetic shift tensor and the inhomogeneous broadening.
Collapse
Affiliation(s)
- Rihards Aleksis
- Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91, Stockholm, Sweden
| | - José P Carvalho
- Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Aleksander Jaworski
- Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Andrew J Pell
- Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91, Stockholm, Sweden.
| |
Collapse
|
9
|
Kageyama H, Yajima T, Tsujimoto Y, Yamamoto T, Tassel C, Kobayashi Y. Exploring Structures and Properties through Anion Chemistry. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2019. [DOI: 10.1246/bcsj.20190095] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Hiroshi Kageyama
- Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8581, Japan
| | - Takeshi Yajima
- Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
| | - Yoshihiro Tsujimoto
- Research Centre for Functional Materials, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Takafumi Yamamoto
- Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8581, Japan
| | - Cedric Tassel
- Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8581, Japan
| | - Yoji Kobayashi
- Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8581, Japan
| |
Collapse
|
10
|
Etman A, Pell AJ, Svedlindh P, Hedin N, Zou X, Sun J, Bernin D. Insights into the Exfoliation Process of V 2O 5· nH 2O Nanosheet Formation Using Real-Time 51V NMR. ACS OMEGA 2019; 4:10899-10905. [PMID: 31460187 PMCID: PMC6648752 DOI: 10.1021/acsomega.9b00727] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 05/29/2019] [Indexed: 06/10/2023]
Abstract
Nanostructured hydrated vanadium oxides (V2O5·nH2O) are actively being researched for applications in energy storage, catalysis, and gas sensors. Recently, a one-step exfoliation technique for fabricating V2O5·nH2O nanosheets in aqueous media was reported; however, the underlying mechanism of exfoliation has been challenging to study. Herein, we followed the synthesis of V2O5·nH2O nanosheets from the V2O5 and VO2 precursors in real time using solution- and solid-state 51V NMR. Solution-state 51V NMR showed that the aqueous solution contained mostly the decavanadate anion [H2V10O28]4- and the hydrated dioxovanadate cation [VO2·4H2O]+, and during the exfoliation process, decavanadate was formed, while the amount of [VO2·4H2O]+ remained constant. The conversion of the solid precursor V2O5, which was monitored with solid-state 51V NMR, was initiated when VO2 was in its monoclinic forms. The dried V2O5·nH2O nanosheets were weakly paramagnetic because of a minor content of isolated V4+. Its solid-state 51V signal was less than 20% of V2O5 and arose from diamagnetic V4+ or V5+.This study demonstrates the use of real-time NMR techniques as a powerful analysis tool for the exfoliation of bulk materials into nanosheets. A deeper understanding of this process will pave the way to tailor these important materials.
Collapse
Affiliation(s)
- Ahmed
S. Etman
- Department
of Materials and Environmental Chemistry, Stockholm University, 10691 Stockholm, Sweden
- Department
of Chemistry, Faculty of Science, Alexandria
University, Ibrahimia, 21321 Alexandria, Egypt
| | - Andrew J. Pell
- Department
of Materials and Environmental Chemistry, Stockholm University, 10691 Stockholm, Sweden
| | - Peter Svedlindh
- Department
of Engineering Sciences, Uppsala University, 75121 Uppsala, Sweden
| | - Niklas Hedin
- Department
of Materials and Environmental Chemistry, Stockholm University, 10691 Stockholm, Sweden
| | - Xiaodong Zou
- Department
of Materials and Environmental Chemistry, Stockholm University, 10691 Stockholm, Sweden
| | - Junliang Sun
- Department
of Materials and Environmental Chemistry, Stockholm University, 10691 Stockholm, Sweden
- College
of Chemistry and Molecular Engineering, Peking University, 100871 Beijing, China
| | - Diana Bernin
- Department
of Materials and Environmental Chemistry, Stockholm University, 10691 Stockholm, Sweden
- Department
of Chemistry and Chemical Engineering, Chalmers
University of Technology, 41296 Gothenburg, Sweden
| |
Collapse
|