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Mow R, Metzroth LJT, Dzara MJ, Russell-Parks GA, Johnson JC, Vardon DR, Pylypenko S, Vyas S, Gennett T, Braunecker WA. Phototriggered Desorption of Hydrogen, Ethylene, and Carbon Monoxide from a Cu(I)-Modified Covalent Organic Framework. J Phys Chem C Nanomater Interfaces 2022; 126:14801-14812. [PMID: 36110496 PMCID: PMC9465684 DOI: 10.1021/acs.jpcc.2c03194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 08/12/2022] [Indexed: 06/15/2023]
Abstract
Materials that are capable of adsorbing and desorbing gases near ambient conditions are highly sought after for many applications in gas storage and separations. While the physisorption of typical gases to high surface area covalent organic frameworks (COFs) occurs through relatively weak intermolecular forces, the tunability of framework materials makes them promising candidates for tailoring gas sorption enthalpies. The incorporation of open Cu(I) sites into framework materials is a proven strategy to increase gas uptake closer to ambient conditions for gases that are capable of π-back-bonding with Cu. Here, we report the synthesis of a Cu(I)-loaded COF with subnanometer pores and a three-dimensional network morphology, namely Cu(I)-COF-301. This study focused on the sorption mechanisms of hydrogen, ethylene, and carbon monoxide with this material under ultrahigh vacuum using temperature-programmed desorption and Kissinger analyses of variable ramp rate measurements. All three gases desorb near or above room temperature under these conditions, with activation energies of desorption (E des) calculated as approximately 29, 57, and 68 kJ/mol, for hydrogen, ethylene, and carbon monoxide, respectively. Despite these strong Cu(I)-gas interactions, this work demonstrated the ability to desorb each gas on-demand below its normal desorption temperature upon irradiation with ultraviolet (UV) light. While thermal imaging experiments indicate that bulk photothermal heating of the COF accounts for some of the photodriven desorption, density functional theory calculations reveal that binding enthalpies are systematically lowered in the COF-hydrogen matrix excited state initiated by UV irradiation, further contributing to gas desorption. This work represents a step toward the development of more practical ambient temperature storage and efficient regeneration of sorbents for applications with hydrogen and π-accepting gases through the use of external photostimuli.
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Affiliation(s)
- Rachel
E. Mow
- Materials
Science Program, Colorado School of Mines, Golden, Colorado 80401, United States
- Department
of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States
- National
Renewable Energy Laboratory, Golden, Colorado 80401, United States
| | - Lucy J. T. Metzroth
- Materials
Science Program, Colorado School of Mines, Golden, Colorado 80401, United States
- National
Renewable Energy Laboratory, Golden, Colorado 80401, United States
| | - Michael J. Dzara
- Department
of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Glory A. Russell-Parks
- Department
of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States
- National
Renewable Energy Laboratory, Golden, Colorado 80401, United States
| | - Justin C. Johnson
- National
Renewable Energy Laboratory, Golden, Colorado 80401, United States
| | - Derek R. Vardon
- National
Renewable Energy Laboratory, Golden, Colorado 80401, United States
| | - Svitlana Pylypenko
- Materials
Science Program, Colorado School of Mines, Golden, Colorado 80401, United States
- Department
of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Shubham Vyas
- Materials
Science Program, Colorado School of Mines, Golden, Colorado 80401, United States
- Department
of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Thomas Gennett
- Materials
Science Program, Colorado School of Mines, Golden, Colorado 80401, United States
- Department
of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States
- National
Renewable Energy Laboratory, Golden, Colorado 80401, United States
| | - Wade A. Braunecker
- Department
of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States
- National
Renewable Energy Laboratory, Golden, Colorado 80401, United States
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2
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Petrovick JG, Radke CJ, Weber AZ. Gas Mass-Transport Coefficients in Ionomer Membranes Using a Microelectrode. ACS Meas Sci Au 2022; 2:208-218. [PMID: 36785864 PMCID: PMC9838820 DOI: 10.1021/acsmeasuresciau.1c00058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Gas permeability, the product of gas diffusivity and Henry's gas-absorption constant, of ionomer membranes is an important transport parameter in fuel cell and electrolyzer research as it governs gas crossover between electrodes and perhaps in the catalyst layers as well. During transient operation, it is important to divide the gas permeability into its constituent properties as they are individually important. Although transient microelectrode measurements have been used previously to separate the gas permeability into these two parameters, inconsistencies remain in the interpretation of the experimental techniques. In this work, a new interpretation methodology is introduced for determining independently diffusivity and Henry's constant of hydrogen and oxygen gases in ionomer membranes (Nafion 211 and Nafion XL) as a function of relative humidity using microelectrodes. Two time regimes are accounted for. At long times, gas permeability is determined from a two-dimensional numerical model that calculates the solubilized-gas concentration profiles at a steady state. At short times, permeability is deconvoluted into diffusivity and Henry's constant by analyzing transient data with an extended Cottrell equation that corrects for actual electrode surface area. Gas permeability and diffusivity increase as relative humidity increases for both gases in both membranes, whereas Henry's constants for both gases decrease with increasing relative humidity. In addition, results for Nafion 211 membranes are compared to a simple phase-separated parallel-diffusion transport theory with good agreement. The two-time-regime analysis and the experimental methodology can be applied to other electrochemical systems to enable greater precision in the calculation of transport parameters and to further understanding of gas transport in fuel cells and electrolyzers.
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Affiliation(s)
- John G. Petrovick
- Department
of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States
- Energy
Conversion Group, Energy Technologies Area, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Clayton J. Radke
- Department
of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States
| | - Adam Z. Weber
- Energy
Conversion Group, Energy Technologies Area, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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Severa G, Bruffey E, Nguyen PQH, Gigante A, Leick N, Kelly C, Finkelstein GJ, Hagemann H, Gennett T, Rocheleau RE, Dera P. Fe 4(OAc) 10[EMIM] 2: Novel Iron-Based Acetate EMIM Ionic Compound. ACS Omega 2021; 6:31907-31918. [PMID: 34870013 PMCID: PMC8637965 DOI: 10.1021/acsomega.1c04670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 10/25/2021] [Indexed: 06/13/2023]
Abstract
We synthesized and characterized a novel iron(II) aceto EMIM coordination compound, which has a simplified empirical formula Fe4(OAc)10[EMIM]2, in two different hydration forms: as anhydrous monoclinic compound and triclinic dihydrate Fe4(OAc)10[EMIM]2·2H2O. The dihydrate compound is isostructural with recently reported Mn4(OAc)10[EMIM]2·2H2O, while the anhydrate is a superstructure of the Mn counterpart, suggesting the existence of solid solutions. Both new Fe compounds contain chains of Fe2+ octahedrally coordinated exclusively by acetate groups. The EMIM moieties do not interact directly with the Fe2+ and contribute to the structural framework of the compound through van der Waals forces and C-H···O hydrogen bonds with the acetate anions. The compounds have a melting temperature of ∼94 °C; therefore, they can be considered metal-containing ionic liquids. Differential thermal analysis indicates three endothermic transitions associated with melting, structural rearrangement in the molten state at about 157 °C, and finally, thermal decomposition of the Fe4(OAc)10[EMIM]2. Thermogravimetric analyses indicate an ∼72 wt % mass loss during the decomposition at 280-325 °C. The Fe4(OAc)10[EMIM]2 compounds have higher thermal stability than their Mn counterparts and [EMIM][OAc] but lower compared to iron(II) acetate. Temperature-programmed desorption coupled with mass spectrometry shows that the decomposition pathway of the Fe4(OAc)10[EMIM]2 involves four distinct regimes with peak temperatures at 88, 200, 267, and 345 °C. The main species observed in the decomposition of the compound are CH3, H2O, N2, CO, OC-CH3, OH-CO, H3C-CO-CH3, and H3C-O-CO-CH3. Variable-temperature infrared vibrational spectroscopy indicates that the phase transition at 160-180 °C is associated with a reorientation of the acetate ions, which may lead to a lower interaction with the [EMIM]+ before the decomposition of the Fe4(OAc)10[EMIM]2 upon further heating. The Fe4(OAc)10[EMIM]2 compounds are porous, plausibly capable of accommodating other types of molecules.
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Affiliation(s)
- Godwin Severa
- Hawai’i
Natural Energy Institute, University of
Hawai’i at Ma̅noa, 1680 East West Road, POST 109, Honolulu, Hawaii 96822, United States
| | - Edward Bruffey
- Hawai’i
Natural Energy Institute, University of
Hawai’i at Ma̅noa, 1680 East West Road, POST 109, Honolulu, Hawaii 96822, United States
| | - Phuong Q. H. Nguyen
- Hawai’i
Institute of Geophysics and Planetology, University of Hawai’i at Ma̅noa, 1680 East West Road, POST 109, Honolulu, Hawaii 96822, United States
| | - Angelina Gigante
- Département
de Chimie Physique, Université de
Genève, 30, quai E. Ansermet, 1211 Geneva 4, Switzerland
| | - Noemi Leick
- National
Renewable Energy Laboratory (NREL), Colorado, Colorado 80401, United States
| | - Colleen Kelly
- Hawai’i
Natural Energy Institute, University of
Hawai’i at Ma̅noa, 1680 East West Road, POST 109, Honolulu, Hawaii 96822, United States
| | - Gregory J. Finkelstein
- Hawai’i
Institute of Geophysics and Planetology, University of Hawai’i at Ma̅noa, 1680 East West Road, POST 109, Honolulu, Hawaii 96822, United States
| | - Hans Hagemann
- Département
de Chimie Physique, Université de
Genève, 30, quai E. Ansermet, 1211 Geneva 4, Switzerland
| | - Thomas Gennett
- National
Renewable Energy Laboratory (NREL), Colorado, Colorado 80401, United States
- Chemistry
Department, Colorado School of Mines, 1012 14th Street, Golden, Colorado 80401, United States
| | - Richard E. Rocheleau
- Hawai’i
Natural Energy Institute, University of
Hawai’i at Ma̅noa, 1680 East West Road, POST 109, Honolulu, Hawaii 96822, United States
| | - Przemyslaw Dera
- Hawai’i
Institute of Geophysics and Planetology, University of Hawai’i at Ma̅noa, 1680 East West Road, POST 109, Honolulu, Hawaii 96822, United States
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Gigante A, Leick N, Lipton AS, Tran B, Strange NA, Bowden M, Martinez MB, Moury R, Gennett T, Hagemann H, Autrey TS. Thermal Conversion of Unsolvated Mg(B 3H 8) 2 to BH 4 - in the Presence of MgH 2. ACS Appl Energy Mater 2021; 4:3737-3747. [PMID: 37153859 PMCID: PMC10156084 DOI: 10.1021/acsaem.1c00159] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
In the search for energy storage materials, metal octahydrotriborates, M(B3H8) n , n = 1 and 2, are promising candidates for applications such as stationary hydrogen storage and all-solid-state batteries. Therefore, we studied the thermal conversion of unsolvated Mg(B3H8)2 to BH4 - as-synthesized and in the presence of MgH2. The conversion of our unsolvated Mg(B3H8)2 starts at ∼100 °C and yields ∼22 wt % of BH4 - along with the formation of (closo-hydro)borates and volatile boranes. This loss of boron (B) is a sign of poor cyclability of the system. However, the addition of activated MgH2 to unsolvated Mg(B3H8)2 drastically increases the thermal conversion to 85-88 wt % of BH4 - while simultaneously decreasing the amounts of B-losses. Our results strongly indicate that the presence of activated MgH2 substantially decreases the formation of (closo-hydro)borates and provides the necessary H2 for the B3H8-to-BH4 conversion. This is the first report of a metal octahydrotriborate system to selectively convert to BH4 - under moderate conditions of temperature (200 °C) in less than 1 h, making the MgB3H8-MgH2 system very promising for energy storage applications.
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Affiliation(s)
- Angelina Gigante
- Département
de Chimie Physique, Université de
Genève, 30, quai E. Ansermet, 1211 Geneva 4, Switzerland
| | - Noemi Leick
- National
Renewable Energy Laboratory, 15013 Denver W Pkway, Golden, Colorado 80401, United States
| | - Andrew S. Lipton
- Environmental
Molecular Division, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Ba Tran
- Physical
Sciences Division, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Nicholas A. Strange
- National
Renewable Energy Laboratory, 15013 Denver W Pkway, Golden, Colorado 80401, United States
- SLAC
National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Mark Bowden
- Environmental
Molecular Division, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Madison B. Martinez
- National
Renewable Energy Laboratory, 15013 Denver W Pkway, Golden, Colorado 80401, United States
| | - Romain Moury
- Département
de Chimie Physique, Université de
Genève, 30, quai E. Ansermet, 1211 Geneva 4, Switzerland
- Institut
des Molécules et des Matériaux du Mans, UMR 6283 CNRS, Le Mans Université, Avenue Olivier Messiaen, 72085 Le Mans Cedex 9, France
| | - Thomas Gennett
- National
Renewable Energy Laboratory, 15013 Denver W Pkway, Golden, Colorado 80401, United States
- Chemistry
Department, Colorado School of Mines, 1012 14th Street, Golden, Colorado 80401, United States
| | - Hans Hagemann
- Département
de Chimie Physique, Université de
Genève, 30, quai E. Ansermet, 1211 Geneva 4, Switzerland
| | - Tom S. Autrey
- Environmental
Molecular Division, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
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5
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Li Y, Van Cleve T, Sun R, Gawas R, Wang G, Tang M, Elabd YA, Snyder J, Neyerlin KC. Modifying the Electrocatalyst-Ionomer Interface via Sulfonated Poly(ionic liquid) Block Copolymers to Enable High-Performance Polymer Electrolyte Fuel Cells. ACS Energy Lett 2020; 5:1726-1731. [PMID: 38434232 PMCID: PMC10906942 DOI: 10.1021/acsenergylett.0c00532] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 03/05/2024]
Abstract
Polymer electrolyte membrane fuel cell (PEMFC) electrodes with a 0.07 mgPt cm-2 Pt/Vulcan electrocatalyst loading, containing only a sulfonated poly(ionic liquid) block copolymer (SPILBCP) ionomer, were fabricated and achieved a ca. 2× enhancement of kinetic performance through the suppression of Pt surface oxidation. However, SPILBCP electrodes lost over 70% of their electrochemical active area at 30% RH because of poor ionomer network connectivity. To combat these effects, electrodes made with a mix of Nafion/SPILBCP ionomers were developed. Mixed Nafion/SPILBCP electrodes resulted in a substantial improvement in MEA performance across the kinetic and mass transport-limited regions. Notably, this is the first time that specific activity values determined from an MEA were observed to be on par with prior half-cell results for Nafion-free Pt/Vulcan systems. These findings present a prospective strategy to improve the overall performance of MEAs fabricated with surface accessible electrocatalysts, providing a pathway to tailor the local electrocatalyst/ionomer interface.
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Affiliation(s)
- Yawei Li
- Chemistry
and Nanoscience Center, National Renewable
Energy Laboratory, Golden, Colorado 80401, United States
| | - Tim Van Cleve
- Chemistry
and Nanoscience Center, National Renewable
Energy Laboratory, Golden, Colorado 80401, United States
| | - Rui Sun
- Department
of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Ramchandra Gawas
- Department
of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania 19104, United States
| | - Guanxiong Wang
- Chemistry
and Nanoscience Center, National Renewable
Energy Laboratory, Golden, Colorado 80401, United States
| | - Maureen Tang
- Department
of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania 19104, United States
| | - Yossef A. Elabd
- Department
of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Joshua Snyder
- Department
of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania 19104, United States
| | - K. C. Neyerlin
- Chemistry
and Nanoscience Center, National Renewable
Energy Laboratory, Golden, Colorado 80401, United States
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