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Nakajima R, Wago H, Taniguchi T, Sasaki Y, Nishiki Y, Awaludin Z, Nakai T, Kato A, Mitsushima S, Kuroda Y. Mesoporous hydrogel electrodes with flexible frameworks exhibiting enhanced mass transport for the oxygen evolution reaction. Chem Commun (Camb) 2024; 60:2536-2539. [PMID: 38329271 DOI: 10.1039/d3cc04632j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Mesoporous hydrogel electrodes with unique flexible mesopores surrounded by CoOOH nanosheets were prepared via the electrochemical deposition of hybrid cobalt hydroxide nanosheets, exhibiting high oxygen evolution reaction activity at a high current density owing to the enhanced mass transport of oxygen molecules.
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Affiliation(s)
- Ritsuki Nakajima
- Department of Chemistry Applications and Life Science, Graduate School of Engineering Science, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama, Kanagawa 240-8501, Japan.
| | - Hiroki Wago
- Department of Chemistry Applications and Life Science, Graduate School of Engineering Science, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama, Kanagawa 240-8501, Japan.
| | - Tatsuya Taniguchi
- Kawasaki Heavy Industries Ltd, 1-1 Kawasaki-cho, Akashi, Hyogo 673-8666, Japan
| | - Yuta Sasaki
- Kawasaki Heavy Industries Ltd, 1-1 Kawasaki-cho, Akashi, Hyogo 673-8666, Japan
| | - Yoshinori Nishiki
- De Nora Permelec Ltd, 2023-15 Endo, Fujisawa, Kanagawa 252-0816, Japan
| | - Zaenal Awaludin
- De Nora Permelec Ltd, 2023-15 Endo, Fujisawa, Kanagawa 252-0816, Japan
| | - Takaaki Nakai
- De Nora Permelec Ltd, 2023-15 Endo, Fujisawa, Kanagawa 252-0816, Japan
| | - Akihiro Kato
- De Nora Permelec Ltd, 2023-15 Endo, Fujisawa, Kanagawa 252-0816, Japan
| | - Shigenori Mitsushima
- Department of Chemistry Applications and Life Science, Graduate School of Engineering Science, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama, Kanagawa 240-8501, Japan.
- Advanced Chemical Energy Research Center, Institute of Advanced Sciences, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama, Kanagawa 240-8501, Japan
| | - Yoshiyuki Kuroda
- Department of Chemistry Applications and Life Science, Graduate School of Engineering Science, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama, Kanagawa 240-8501, Japan.
- Advanced Chemical Energy Research Center, Institute of Advanced Sciences, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama, Kanagawa 240-8501, Japan
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2
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Nakajima R, Taniguchi T, Sasaki Y, Nishiki Y, Awaludin Z, Nakai T, Kato A, Mitsushima S, Kuroda Y. Principles of Self-Repairing Ability of Tripodal Ligand-Stabilized Hybrid Cobalt Hydroxide Nanosheets for Alkaline Water Electrolysis. CHEMSUSCHEM 2023; 16:e202300384. [PMID: 37255484 DOI: 10.1002/cssc.202300384] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 05/26/2023] [Accepted: 05/31/2023] [Indexed: 06/01/2023]
Abstract
Self-repairing catalysts are promising new materials for achieving long lifetime of alkaline water electrolyzers powered by renewable energy. Catalytic nanoparticles dispersed in an electrolyte were deposited on the anode to repair a catalyst layer by electrolysis. A hybrid cobalt hydroxide nanosheet modified with tris(hydroxymethyl)aminomethane on the surface (Co-ns) was used as a catalyst. Assuming a pseudo-first-order process, the rate constant of an electrochemical deposition was linearly correlated with the electrode potential during electrolysis. Thus, it is expected that the repair of the catalyst is automatically controlled by changes in the oxygen evolution reaction (OER) overpotential. The essential step of the electrochemical deposition was the anodic oxidation of Co2+ to Co3+ . Surface modification of Co-ns protects Co2+ against the autooxidation of Co2+ caused by the dissolved oxygen. The redox properties and organic modification of Co-ns make them well-suited for the self-repairing of anode catalysts.
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Affiliation(s)
- Ritsuki Nakajima
- Department of Chemistry Applications and Life Science, Graduate School of Engineering Science, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama Kanagawa, 240-8501, Japan
| | - Tatsuya Taniguchi
- Kawasaki Heavy Industries Ltd., 1-1 Kawasaki-cho, Akashi, Hyogo, 673-8666, Japan
| | - Yuta Sasaki
- Kawasaki Heavy Industries Ltd., 1-1 Kawasaki-cho, Akashi, Hyogo, 673-8666, Japan
| | - Yoshinori Nishiki
- De Nora Permelec Ltd., 2023-15 Endo, Fujisawa, Kanagawa, 252-0816, Japan
| | - Zaenal Awaludin
- De Nora Permelec Ltd., 2023-15 Endo, Fujisawa, Kanagawa, 252-0816, Japan
| | - Takaaki Nakai
- De Nora Permelec Ltd., 2023-15 Endo, Fujisawa, Kanagawa, 252-0816, Japan
| | - Akihiro Kato
- De Nora Permelec Ltd., 2023-15 Endo, Fujisawa, Kanagawa, 252-0816, Japan
| | - Shigenori Mitsushima
- Department of Chemistry Applications and Life Science, Graduate School of Engineering Science, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama Kanagawa, 240-8501, Japan
- Advanced Chemical Energy Research Center, Institute of Advanced Sciences, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama Kanagawa, 240-8501, Japan
| | - Yoshiyuki Kuroda
- Department of Chemistry Applications and Life Science, Graduate School of Engineering Science, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama Kanagawa, 240-8501, Japan
- Advanced Chemical Energy Research Center, Institute of Advanced Sciences, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama Kanagawa, 240-8501, Japan
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3
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Ferreira EB, Gibaldi M, Okada R, Kuroda Y, Mitsushima S, Jerkiewicz G. Tunable Method for the Preparation of Layered Double Hydroxide Nanoparticles and Mesoporous Mixed Metal Oxide Electrocatalysts for the Oxygen Evolution Reaction. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023. [PMID: 37236238 DOI: 10.1021/acs.langmuir.3c00617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Preparation of high-performance and durable electrocatalysts for anion exchange membrane water electrolysis is a crucial step toward the broad implementation of this technology. Here, we present an easily tunable, one-step hydrothermal method for the preparation of Ni-based (NiX, X = Co, Fe) layered double hydroxide nanoparticles (LDHNPs) for the oxygen evolution reaction (OER), using tris(hydroxymethyl)aminomethane (Tris-NH2) for particle growth control. The LDHNPs are used as building blocks of mesoporous mixed metal oxides (MMOs) with a block copolymer template (Pluronic F127), followed by thermal treatment at 250 °C. NiX MMOs have a significantly larger surface area compared to the analogous LDHNPs. NiX LDHNPs and MMOs exhibit excellent performance and long-term cycling stability, making them promising OER catalysts. Moreover, this versatile method can be easily tailored and scaled up for the preparation of platinum group metal-free electrocatalysts for other reactions of interest, which highlights the relevance of this work to the field of electrocatalysis.
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Affiliation(s)
- Eduardo B Ferreira
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario K7L 3N6, Canada
| | - Marco Gibaldi
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario K7L 3N6, Canada
| | - Ryuki Okada
- Graduate School of Engineering Science, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan
| | - Yoshiyuki Kuroda
- Graduate School of Engineering Science, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan
- Advanced Chemical Energy Research Center, Institute of Advanced Sciences, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan
| | - Shigenori Mitsushima
- Graduate School of Engineering Science, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan
- Advanced Chemical Energy Research Center, Institute of Advanced Sciences, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan
| | - Gregory Jerkiewicz
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario K7L 3N6, Canada
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4
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Oda K, Kuroda Y, Mitsushima S. Investigation of Charge–Discharging Behavior of Metal Oxide–Based Anode Electrocatalysts for Alkaline Water Electrolysis to Suppress Degradation due to Reverse Current. Electrocatalysis (N Y) 2023. [DOI: 10.1007/s12678-023-00815-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
AbstractIn the bipolar-type alkaline water electrolysis powered by renewable energy, electrocatalysts are degraded by repeated potential change associated with the generation of reverse current. If an electrode has large discharge capacity, the opposite electrode on the same bipolar plate is degraded by the reverse current. In this study, discharge capacity of various transition metal-based electrocatalysts was investigated to clarify the determining factors of electrocatalysts on the reverse current and durability. The discharge capacities from 1.5 to 0.5 V vs. RHE (Qdc,0.5) of electrocatalysts are proportional to the surface area in most cases. The proportionality coefficient, corresponding to the specific capacity, is 1.0 C·m–2 for Co3O4 and 2.3 C·m–2 for manganese-based electrocatalysts. The substitution of Co3+ in Co3O4 with Ni3+ increased Qdc,0.5. The upper limit of theoretical specific capacity for Co3O4 is estimated to be 1.699 C·m–2, meaning the former and latter cases correspond to 2- and 1-electron reactions, respectively, per a cation at the surface. The discharge capacities of the elctrocatalysts increased because of the dissolution and recrystallization of nickel and/or cobalt into metal hydroxides. The increase in the capacities of Co3O4 and NiCo2O4 during ten charge–discharge cycles was below 2–9% and 0.5–38%, respectively. Therefore, if a cathode electrocatalyst with relatively low redox durability is used on the one side of a bipolar plate, it is necessary to control optimum discharge capacity of the anode by changing surface area and constituent metal cations to minimize the generation of reverse current.
Graphical Abstract
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5
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Nara Y, Tanaka M, Nagasawa K, Kuroda Y, Mitsushima S, Kawakami H. Development of highly alkaline stable anion conductive polymers with fluorene backbone for water electrolysis. POLYM ADVAN TECHNOL 2022. [DOI: 10.1002/pat.5752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Yuri Nara
- Department of Applied Chemistry Tokyo Metropolitan University Tokyo Japan
| | - Manabu Tanaka
- Department of Applied Chemistry Tokyo Metropolitan University Tokyo Japan
- Research Center for Hydrogen Energy‐based Society (ReHES) Tokyo Metropolitan University Tokyo Japan
| | - Kensaku Nagasawa
- Institute of Advanced Sciences Yokohama National University Yokohama Kanagawa Japan
| | - Yoshiyuki Kuroda
- Institute of Advanced Sciences Yokohama National University Yokohama Kanagawa Japan
- Graduate School of Engineering Science Yokohama National University Yokohama Kanagawa Japan
| | - Shigenori Mitsushima
- Institute of Advanced Sciences Yokohama National University Yokohama Kanagawa Japan
- Graduate School of Engineering Science Yokohama National University Yokohama Kanagawa Japan
| | - Hiroyoshi Kawakami
- Department of Applied Chemistry Tokyo Metropolitan University Tokyo Japan
- Research Center for Hydrogen Energy‐based Society (ReHES) Tokyo Metropolitan University Tokyo Japan
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6
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Cossar E, Agarwal K, Nguyen VB, Safari R, Botton GA, Baranova EA. Highly Active Nickel–Iron Nanoparticles With and Without Ceria for the Oxygen Evolution Reaction. Electrocatalysis (N Y) 2021. [DOI: 10.1007/s12678-021-00674-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Muramatsu K, Kuroda Y, Wada H, Shimojima A, Kuroda K. Hydrolysis of Methoxylated Nickel Hydroxide Leading to Single-Layer Ni(OH) 2 Nanosheets. Inorg Chem 2021; 60:7094-7100. [PMID: 33939399 DOI: 10.1021/acs.inorgchem.0c03830] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Various methods for the preparation of inorganic nanosheets have been established and they have contributed to the substantial development of the research on diverse two-dimensional materials. Covalent surface modification of layered metal hydroxides with alkoxy groups is known to effectively weaken the interactions between layers, although the modified ligands are irreversibly immobilized. This study proposes the use of methanol as a removable surface modifier forming monodentate alkoxy bonds to prepare nickel hydroxide nanosheets through hydrolysis. Methoxylated layered nickel hydroxide, consisting of randomly stacked nano-sized nickel hydroxide sheets (10-20 nm in size) having Ni-OCH3 groups on its surface, was synthesized in a powder form through the precipitation reaction of a nickel salt in methanol at room temperature. After dispersing the aggregated methoxylated nickel hydroxide in water, single-layer nickel hydroxide nanosheets with a thickness of 1.2 nm and a lateral size of 460 nm at maximum, which is larger than the size of original methoxylated nickel hydroxide were found in the suspension. The time-course experiments during hydrolysis suggested that two-dimensional crystal growth of exfoliated nickel hydroxide sheets proceeded, resulting in the formation of the nanosheets. Moreover, single-layer and nano-sized cobalt hydroxide was prepared through a similar manner. This work demonstrates that two-dimensional alkoxides consisting of polymeric M-O-M bonds are useful precursors for the design of metal-hydroxide-based nanomaterials.
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Affiliation(s)
- Keisuke Muramatsu
- Department of Advanced Science and Engineering, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Yoshiyuki Kuroda
- Graduate School of Engineering Science, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan.,Advanced Chemical Energy Research Center, Institute of Advanced Sciences, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan
| | - Hiroaki Wada
- Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Atsushi Shimojima
- Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan.,Kagami Memorial Research Institute for Materials Science and Technology, Waseda University, 2-8-26 Nishiwaseda, Shinjuku-ku, Tokyo 169-0051, Japan
| | - Kazuyuki Kuroda
- Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan.,Kagami Memorial Research Institute for Materials Science and Technology, Waseda University, 2-8-26 Nishiwaseda, Shinjuku-ku, Tokyo 169-0051, Japan
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8
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Muramatsu K, Kamiusuki Y, Kuroda Y, Wada H, Shimojima A, Kuroda K. Direct bottom-up synthesis of size-controlled monodispersed single-layer magnesium hydroxide nanosheets modified with tripodal ligands. Dalton Trans 2021; 50:3121-3126. [PMID: 33616140 DOI: 10.1039/d1dt00207d] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Conventional top-down methods for preparing inorganic nanosheets possess fundamental challenges of morphological control. Herein, the direct synthesis of organically modified single-layer magnesium hydroxide nanosheets with narrow size distribution was achieved by the in situ modification of magnesium hydroxide with a tripodal ligand, tris(hydroxymethyl)aminomethane.
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Affiliation(s)
- Keisuke Muramatsu
- Department of Advanced Science and Engineering, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Yuya Kamiusuki
- Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan.
| | - Yoshiyuki Kuroda
- Graduate School of Engineering Science, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan. and Advanced Chemical Energy Research Center, Institute of Advanced Sciences, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan
| | - Hiroaki Wada
- Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan.
| | - Atsushi Shimojima
- Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan. and Kagami Memorial Research Institute for Materials Science and Technology, Waseda University, 2-8-26 Nishiwaseda, Shinjuku-ku, Tokyo 169-0051, Japan
| | - Kazuyuki Kuroda
- Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan. and Kagami Memorial Research Institute for Materials Science and Technology, Waseda University, 2-8-26 Nishiwaseda, Shinjuku-ku, Tokyo 169-0051, Japan
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9
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ABDEL HALEEM A, NAGASAWA K, KURODA Y, NISHIKI Y, ZAENAL A, MITSUSHIMA S. A New Accelerated Durability Test Protocol for Water Oxidation Electrocatalysts of Renewable Energy Powered Alkaline Water Electrolyzers. ELECTROCHEMISTRY 2021. [DOI: 10.5796/electrochemistry.20-00156] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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10
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Todoroki N, Wadayama T. Electrochemical stability of stainless-steel-made anode for alkaline water electrolysis: Surface catalyst nanostructures and oxygen evolution overpotentials under applying potential cycle loading. Electrochem commun 2021. [DOI: 10.1016/j.elecom.2020.106902] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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11
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Muramatsu K, Hayashi S, Kuroda Y, Oka Y, Wada H, Shimojima A, Kuroda K. Selective Covalent Modification of Layered Double Hydroxide Nanoparticles with Tripodal Ligands on Outer and Interlayer Surfaces. Inorg Chem 2020; 59:6110-6119. [PMID: 32186868 DOI: 10.1021/acs.inorgchem.0c00192] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Layered double hydroxides (LDHs) have occupied an important place in the fields of catalysts, electrocatalysts, and fillers, and their applicability can be greatly enhanced by interlayer organic modifications. In contrast to general organic modification based on noncovalent modification using ionic organic species, this study has clarified in situ interlayer covalent modification of LDH nanoparticles (LDHNPs) with the tripodal ligand tris(hydroxymethyl)aminomethane (Tris-NH2). Interlayer-modified CoAl LDHNPs were obtained by a one-pot hydrothermal treatment of an aqueous solution containing metal salts and Tris-NH2 at 180 °C for 24 h. Tris-NH2 was covalently bonded on the interlayer surface of LDHNPs. Interlayer-modified NiAl LDHNPs were also similarly synthesized. Some comparative experiments under different conditions indicate that the important parameters for interlayer modification are the number of bonding sites per a modifier, the electronegativity of a constituent divalent metal element, and the concentration of a modifier; this is because these parameters affect the hydrolytic stability of alkoxy-metal bonds between a modifier and a layer of LDHNPs. The synthesis of interlayer-modified MgAl LDHNPs was achieved by adjusting these parameters. This achievement will enable new potential applications because modification of only the outer surface has been achieved until now. Interlayer-modified LDHNPs possessing CO32- in the interlayer space were delaminated into monolayers under ultrasonication in water. The proposed method provides a rational approach for interlayer modification and facile delamination of LDHNPs.
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Affiliation(s)
- Keisuke Muramatsu
- Department of Advanced Science and Engineering, Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Shiori Hayashi
- Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Yoshiyuki Kuroda
- Green Hydrogen Research Center, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan
| | - Yuya Oka
- Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Hiroaki Wada
- Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Atsushi Shimojima
- Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan.,Kagami Memorial Research Institute for Materials Science and Technology, 2-8-26 Nishiwaseda, Shinjuku-ku, Tokyo 169-0051, Japan
| | - Kazuyuki Kuroda
- Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan.,Kagami Memorial Research Institute for Materials Science and Technology, 2-8-26 Nishiwaseda, Shinjuku-ku, Tokyo 169-0051, Japan
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12
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Abstract
Alkaline water electrolysis is a key technology for large-scale hydrogen production powered by renewable energy. As conventional electrolyzers are designed for operation at fixed process conditions, the implementation of fluctuating and highly intermittent renewable energy is challenging. This contribution shows the recent state of system descriptions for alkaline water electrolysis and renewable energies, such as solar and wind power. Each component of a hydrogen energy system needs to be optimized to increase the operation time and system efficiency. Only in this way can hydrogen produced by electrolysis processes be competitive with the conventional path based on fossil energy sources. Conventional alkaline water electrolyzers show a limited part-load range due to an increased gas impurity at low power availability. As explosive mixtures of hydrogen and oxygen must be prevented, a safety shutdown is performed when reaching specific gas contamination. Furthermore, the cell voltage should be optimized to maintain a high efficiency. While photovoltaic panels can be directly coupled to alkaline water electrolyzers, wind turbines require suitable converters with additional losses. By combining alkaline water electrolysis with hydrogen storage tanks and fuel cells, power grid stabilization can be performed. As a consequence, the conventional spinning reserve can be reduced, which additionally lowers the carbon dioxide emissions.
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