1
|
Confalonieri G, Vezzalini G, Quattrini F, Quartieri S, Dejoie C, Arletti R. Ce-exchange capacity of zeolite L in different cationic forms: a structural investigation. J Appl Crystallogr 2021. [DOI: 10.1107/s1600576721010827] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Cerium exchange by microporous materials, such as zeolites, has important applications in different fields, for example, rare earth element recovery from waste or catalytic processes. This work investigated the Ce-exchange capacity of zeolite L in three different cationic forms (the as-synthesized K form and Na- and NH4-exchanged ones) from a highly concentrated solution. Chemical analyses and structural investigations allowed determination of the mechanisms involved in the exchanges and give new insights into the interactions occurring between the cations and the zeolite framework. Different cation sites are involved: (i) K present in the original LTL in the cancrinite cage (site KB) cannot be exchanged; (ii) the cations in KD (in the 12-membered ring channel) are always exchanged; while (iii) site KC (in the eight-membered ring channel) is involved only when K+ is substituted by NH4
+, thus promoting a higher exchange rate for NH4
+ → K+ than for Na+ → K+. In the Ce-exchanged samples, a new site occupied by Ce appears in the centre of the main channel, accompanied by an increase in the number of and a rearrangement of H2O molecules. In terms of Ce exchange, the three cationic forms behave similarly, from both the chemical and structural point of view (exchanged Ce ranges from 38 to 42% of the pristine cation amount). Beyond the intrinsic structural properties of the zeolite L framework, the Ce exchange seems thus also governed by the water coordination sphere of the cation. Complete Ce recovery from zeolite pores was achieved.
Collapse
|
2
|
Sarmadi N, Gharabaghi M, Tamadoni Saray M, Darestani M, Garman D, Koshy P, S Mofarah S, Sorrell CC. Highly Mesoporous Hybrid Transition Metal Oxide Nanowires for Enhanced Adsorption of Rare Earth Elements from Wastewater. Inorg Chem 2021; 60:175-184. [PMID: 33337147 DOI: 10.1021/acs.inorgchem.0c02762] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Removal of rare earth elements (REEs) from industrial wastewater is a continual challenge. To date, several approaches to the synthesis of nanoadsorbants for this application have been reported, although these are characterized by insufficient adsorption capacity and limitations in cycling stability. The present work reports the fabrication and performance of hierarchical hybrid transition metal oxide (TMO) nanowires deposited on carbon fibers. An ordered assembly of hybrid TMO nanowires exhibits an outstanding adsorbance of 1000 mg·g-1 of REEs with 93% recyclability. This superior performance is attributed to the unique mesoporous architecture of the nanowires, which exhibits a high surface area of 122 cm3·g-1. Further, rapid adsorption/desorption of the REEs reveals minimal morphological alteration and hence high structural stability of these hybrid TMO nanowires after multiple cycles. The ready accessibility of the adsorption sites at crystallite boundaries and the surfaces as well as rapid adsorption of the REEs on the mesoporous nanostructure facilitate considerable adsorption capacity, improved structural stability, and extended cyclability, all of which suggest the potential for this material in REE extraction.
Collapse
Affiliation(s)
- Negin Sarmadi
- School of Materials Science and Engineering, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Mahdi Gharabaghi
- School of Mining Engineering, University of Tehran, Tehran, Iran
| | - Mahmoud Tamadoni Saray
- Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, Illinois 60607, United States
| | - Mariam Darestani
- School of Mechanical Engineering, Western Sydney University, Sydney, NSW 2751, Australia
| | - David Garman
- School of Freshwater Science, University of Wisconsin - Milwaukee, Milwaukee, Wisconsin 53204, United States
| | - Pramod Koshy
- School of Materials Science and Engineering, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Sajjad S Mofarah
- School of Materials Science and Engineering, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Charles C Sorrell
- School of Materials Science and Engineering, UNSW Sydney, Sydney, NSW 2052, Australia
| |
Collapse
|
3
|
Buchanan CA, Ko E, Cira S, Balasubramanian M, Goldsmith BR, Singh N. Structures and Free Energies of Cerium Ions in Acidic Electrolytes. Inorg Chem 2020; 59:12552-12563. [PMID: 32845625 DOI: 10.1021/acs.inorgchem.0c01645] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The Ce3+/Ce4+ redox potential changes with the electrolyte, which could be due to unequal anion complexation free energies between Ce3+ and Ce4+ or a change in the solvent electrostatic screening. Ce complexation with anions and solvent screening also affect the solubility of Ce and charge transfer kinetics for electrochemical reactions involving waste remediation and energy storage. We report the structures and free energies of cerium complexes in seven acidic electrolytes based on Extended X-ray Absorption Fine Structure, UV-vis, and Density Functional Theory calculations. Ce3+ coordinates with nine water molecules as [Ce(H2O)9]3+ in all studied electrolytes. However, Ce4+ complexes with anions in all electrolytes except HClO4. Thus, our results suggest that Ce4+-anion complexation leads to the large shifts in standard redox potential. Long range screening effects are smaller than the anion complexation energies but could be responsible for changes in the Ce solubility with acid.
Collapse
Affiliation(s)
- Cailin A Buchanan
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States.,Catalysis Science and Technology Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Eunbyeol Ko
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States.,Catalysis Science and Technology Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Spencer Cira
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Mahalingam Balasubramanian
- Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Bryan R Goldsmith
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States.,Catalysis Science and Technology Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Nirala Singh
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States.,Catalysis Science and Technology Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| |
Collapse
|
4
|
Rudolph WW, Irmer G. Raman spectroscopic characterization of light rare earth ions: La 3+, Ce 3+, Pr 3+, Nd 3+ and Sm 3+ - hydration and ion pair formation. Dalton Trans 2018; 46:4235-4244. [PMID: 28280811 DOI: 10.1039/c7dt00008a] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Raman spectra of aqueous La3+, Ce3+, Pr3+, Nd3+ and Sm3+ - perchlorate solutions were measured and weak strongly polarized Raman bands were detected at 343 cm-1, 344 cm-1, 347 cm-1, 352 cm-1 and 363 cm-1, respectively. The full width at half height for these bands is quite broad (∼50 cm-1) in the isotropic spectrum and the band width increases with increasing solute concentration. The polarized Raman bands were assigned to the breathing modes of the nona-aqua ions of the mentioned rare earth ions. Published structural results confirmed that these ions exist as nona-hydrates in aqueous solutions [Ln(H2O)9]3+. The Ln-O bond distances of these rare earth ions correlate well with the band positions of the nona-aqua ions [Ln(OH2)9]+3 (Ln = La3+, Ce3+, Pr3+, Nd3+ and Sm3+) and the force constants were calculated for these breathing modes. The strength of the force constants increase with decreasing the Ln-O bond distances (La-O > Ce-O > Pr-O > Nd-O > Sm-O). While the fully hydrated ions are stable in dilute perchlorate solutions (∼0.2 mol L-1), in concentrated perchlorate solutions outer-sphere ion pairs and contact ion pairs are formed (C > 1.5 mol L-1). In a hydrate melt at 161 °C of Ce(ClO4)3 plus 6H2O, the contact ion pairs are the dominate species. The Raman bands of the ligated perchlorate and the Ce-O breathing mode of the partially hydrated ion pair at 326 cm-1 were measured and characterized. In cerium chloride solutions chloro-complex formation was detected over the measured concentration range from 0.270-2.167 mol L-1. The chloro-complexes in CeCl3(aq) are weak and diminish rapidly with dilution and disappear at a concentration <0.1 mol L-1. In a CeCl3 solution, with additional HCl, a series of chloro-complex species of the type [Ce(OH2)9-nCln]+3-n (n = 1, 2) were detected.
Collapse
Affiliation(s)
- Wolfram W Rudolph
- Medizinische Fakultät der TU Dresden, Institut für Virologie im MTZ, Fiedlerstr. 42, 01307 Dresden, Germany.
| | - Gert Irmer
- Technische Universität Bergakademie Freiberg, Institut für Theoretische Physik, Leipziger Str. 23, 09596 Freiberg, Germany
| |
Collapse
|
5
|
Canaval LR, Rode BM. The hydration properties of Eu(II) and Eu(III): An ab initio quantum mechanical molecular dynamics study. Chem Phys Lett 2015. [DOI: 10.1016/j.cplett.2014.10.060] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
6
|
Hitzenberger M, Hofer TS, Weiss AKH. Solvation properties and behaviour of lutetium(III) in aqueous solution—A quantum mechanical charge field (QMCF) study. J Chem Phys 2013; 139:114306. [DOI: 10.1063/1.4820879] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
|