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Lund A, Manohara GV, Song AY, Jablonka KM, Ireland CP, Cheah LA, Smit B, Garcia S, Reimer JA. Characterization of Chemisorbed Species and Active Adsorption Sites in Mg-Al Mixed Metal Oxides for High-Temperature CO 2 Capture. Chem Mater 2022; 34:3893-3901. [PMID: 35573112 PMCID: PMC9097159 DOI: 10.1021/acs.chemmater.1c03101] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [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: 09/07/2021] [Revised: 03/17/2022] [Indexed: 06/15/2023]
Abstract
Mg-Al mixed metal oxides (MMOs), derived from the decomposition of layered double hydroxides (LDHs), have been purposed as adsorbents for CO2 capture of industrial plant emissions. To aid in the design and optimization of these materials for CO2 capture at 200 °C, we have used a combination of solid-state nuclear magnetic resonance (ssNMR) and density functional theory (DFT) to characterize the CO2 gas sorption products and determine the various sorption sites in Mg-Al MMOs. A comparison of the DFT cluster calculations with the observed 13C chemical shifts of the chemisorbed products indicates that mono- and bidentate carbonates are formed at the Mg-O sites with adjacent Al substitution of an Mg atom, while the bicarbonates are formed at Mg-OH sites without adjacent Al substitution. Quantitative 13C NMR shows an increase in the relative amount of strongly basic sites, where the monodentate carbonate product is formed, with increasing Al/Mg molar ratios in the MMOs. This detailed understanding of the various basic Mg-O sites presented in MMOs and the formation of the carbonate, bidentate carbonate, and bicarbonate chemisorbed species yields new insights into the mechanism of CO2 adsorption at 200 °C, which can further aid in the design and capture capacity optimization of the materials.
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Affiliation(s)
- Alicia Lund
- Materials
Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department
of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States
| | - G. V. Manohara
- Research
Center for Carbon Solutions (RCCS), School of Engineering and Physical
Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K.
| | - Ah-Young Song
- Materials
Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department
of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States
| | - Kevin Maik Jablonka
- Laboratory
of Molecular Simulation (LSMO), Institut
des Sciences et Ingénierie Chimiques, École Polytechnique
Fédérale de Lausanne (EPFL), Rue de l’Industrie 17, Sion CH-1951, Switzerland
| | - Christopher P. Ireland
- Laboratory
of Molecular Simulation (LSMO), Institut
des Sciences et Ingénierie Chimiques, École Polytechnique
Fédérale de Lausanne (EPFL), Rue de l’Industrie 17, Sion CH-1951, Switzerland
| | - Li Anne Cheah
- Research
Center for Carbon Solutions (RCCS), School of Engineering and Physical
Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K.
| | - Berend Smit
- Laboratory
of Molecular Simulation (LSMO), Institut
des Sciences et Ingénierie Chimiques, École Polytechnique
Fédérale de Lausanne (EPFL), Rue de l’Industrie 17, Sion CH-1951, Switzerland
| | - Susana Garcia
- Research
Center for Carbon Solutions (RCCS), School of Engineering and Physical
Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K.
| | - Jeffrey A. Reimer
- Materials
Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department
of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States
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Cheah LA, Manohara GV, Maroto‐Valer MM, Garcia S. Layered Double Hydroxide (LDH)‐Derived Mixed Metal Oxides (MMOs): A Systematic Crystal‐Chemical Approach to Investigating the Chemical Composition and its Effect on High Temperature CO
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capture. ChemistrySelect 2020. [DOI: 10.1002/slct.201904447] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Li Anne Cheah
- Research Centre for Carbon Solutions (RCCS)School of Engineering and Physical SciencesHeriot-Watt University Edinburgh EH14 4AS United Kingdom
| | - G. V. Manohara
- Research Centre for Carbon Solutions (RCCS)School of Engineering and Physical SciencesHeriot-Watt University Edinburgh EH14 4AS United Kingdom
| | - M. Mercedes Maroto‐Valer
- Research Centre for Carbon Solutions (RCCS)School of Engineering and Physical SciencesHeriot-Watt University Edinburgh EH14 4AS United Kingdom
| | - Susana Garcia
- Research Centre for Carbon Solutions (RCCS)School of Engineering and Physical SciencesHeriot-Watt University Edinburgh EH14 4AS United Kingdom
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Abstract
Detection of the auditory steady-state responses (ASSRs) is a difficult task, its main technical impediment is no other than the excessively lengthy recording time required for the estimation process due to the extremely low signal-to-noise ratio (SNR). To improve the detection rate of ASSRs, a new observer-based real-time ASSR detector is derived as an alternate solution to the existing methods. The ASSR detector has a simple structure, and provides fast and reliable signal detection. Simulation and experimental recorded data were used to evaluate the performances of the proposed approach. Compared with the conventional methods, the proposed method requires shorter recording time which could be proven as a valuable hearing screening or diagnostic tool.
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Affiliation(s)
- L A Cheah
- Department of Engineering, University of Hull, HU6 7RX, UK.
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