Catalyze hydrolysis reaction for hydrogen generation by Mg/Mg2Ca nanolamellar structure in Mg–Ca alloys

Uchiyama, Tomoharu; Ando, Daisuke; Sutou, Yuji

doi:10.1016/j.jallcom.2022.165767

“…Therefore, to induce hydrogen generation, some chemical or physical activation methods should be applied [20][21][22][23][24]. The most extensively investigated ones include high reaction temperatures (above 100 • C) [25][26][27][28][29][30][31][32], various acidic [33][34][35], alkali (for aluminum) [36][37][38][39] and salt (NaCl, KCl, MgCl 2 , NiCl 2 , CoCl 2 , CuCl 2 , AlCl 3 ) [40][41][42][43][44][45][46][47][48] solutions, liquid metal embrittlement (for aluminum) [49][50][51], alloying with metals like Ca, Ni, Sn, Fe, Li, Zn, Bi, Cu (brand-new or recovered from electronic and electrical waste) [52][53][54][55][56][57][58][59][60][61], preparation of composite powders with metal (Ni, Nd, Bi, Zn, In, Wood's alloy, etc.) [62][63][64][65]…”

Section: Introductionmentioning

confidence: 99%

Microstructural Transformation and Hydrogen Generation Performance of Magnesium Scrap Ball Milled with Devarda’s Alloy

Buryakovskaya

¹

,

Vlaskin

²

2022

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A method for magnesium scrap transformation into highly efficient hydroreactive material was elaborated. Tested samples were manufactured of magnesium scrap with no additives, or 5 and 10 wt.% Devarda’s alloy, by ball milling for 0.5, 1, 2, and 4 h. Their microstructural evolution and reaction kinetics in 3.5 wt.% NaCl solution were investigated. For the samples with additives and of scrap only, microstructural evolution included the formation of large plane-shaped pieces (0.5 and 1 h) with their further transformation into small compacted solid-shaped objects (2 and 4 h), along with accumulation of crystal lattice imperfections favoring pitting corrosion, and magnesium oxidation with residual oxygen under prolonged (4 h) ball milling, resulting in the lowest reactions rates. Modification with Devarda’s alloy accelerated microstructural evolution (during 0.5–1 h) and the creation of ‘microgalvanic cells’, enhancing magnesium galvanic corrosion with hydrogen evolution. The 1 h milled samples, with 5 wt.% Devarda’s alloy and without additives, provided the highest hydrogen yields of (95.36 ± 0.38)% and (91.12 ± 1.19)%; maximum reaction rates achieved 470.9 and 143.4 mL/g/min, respectively. Such high results were explained by the combination of the largest specific surface areas, accumulated lattice imperfections, and ‘microgalvanic cells’ (from additive). The optimal values were 1 h of milling and 5 wt.% of additive.

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“…[9] Hydrogen generation by reactive metals hydrolysis provides an economical strategy for on-site hydrogen supply with high capacity, operation flexibility, and easy separation of H 2 and O 2 . [10] To date, a series of reactive metals/ mediators have been adopted, such as Mg, [11] Al, [12] Si, [13] NaBH 4 , [14] NH 3 BH 3 , [15] H 6 SiW 12 O 40 , [3b] and H 3 PMo 12 O 40 . [16] The usual first step is to convert electricity to reactive mediators by electrolysis, i.e., the electric energy is stored in the reactive mediator.…”

Section: Introductionmentioning

confidence: 99%

Rechargeable Zn‐H₂O hydrolysis battery for hydrogen storage and production

Cai,

Shi,

Zhang

et al. 2024

Angew Chem Int Ed

0

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Reactive metals hydrolysis offers significant advantages for hydrogen storage and production. However, the regeneration of common reactive metals (e.g., Mg, Al, etc.) is energy‐intensive and produces unwanted byproducts such as CO2 and Cl2. Herein, we employ Zn as a reactive mediator that can be easily regenerated by electrolysis of ZnO in an alkaline solution with a Faradaic efficiency of > 99.9%. H2 is produced in the same electrolyte by constructing a Zn‐H2O hydrolysis battery consisting of a Zn anode and a Raney‐Ni cathode to unlock the Zn‐H2O reaction. The entire two‐step water splitting reaction with a net energy efficiency of 70.4% at 80 oC and 50 mA cm‐2. Additionally, the Zn‐H2O system can be charged using renewable energy to produce H2 on demand and runs for 600 cycles only sacrificing 3.76% energy efficiency. DFT calculations reveal that the desorption of H* on Raney‐Ni (‐0.30 eV) is closer to zero compared with that on Zn (‐0.87 eV), indicating a faster desorption of H* at low overpotential. Further, a 24 Ah electrolyzer is demonstrated to produce H2 with a net energy efficiency of 65.5%, which holds promise for its real application.

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“…[9] Hydrogen generation by reactive metals hydrolysis provides an economical strategy for on-site hydrogen supply with high capacity, operation flexibility, and easy separation of H 2 and O 2 . [10] To date, a series of reactive metals/ mediators have been adopted, such as Mg, [11] Al, [12] Si, [13] NaBH 4 , [14] NH 3 BH 3 , [15] H 6 SiW 12 O 40 , [3b] and H 3 PMo 12 O 40 . [16] The usual first step is to convert electricity to reactive mediators by electrolysis, i.e., the electric energy is stored in the reactive mediator.…”

Section: Introductionmentioning

confidence: 99%

Rechargeable Zn‐H₂O hydrolysis battery for hydrogen storage and production

Cai,

Shi,

Zhang

et al. 2024

Angewandte Chemie

2

0

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Reactive metals hydrolysis offers significant advantages for hydrogen storage and production. However, the regeneration of common reactive metals (e.g., Mg, Al, etc.) is energy‐intensive and produces unwanted byproducts such as CO2 and Cl2. Herein, we employ Zn as a reactive mediator that can be easily regenerated by electrolysis of ZnO in an alkaline solution with a Faradaic efficiency of > 99.9%. H2 is produced in the same electrolyte by constructing a Zn‐H2O hydrolysis battery consisting of a Zn anode and a Raney‐Ni cathode to unlock the Zn‐H2O reaction. The entire two‐step water splitting reaction with a net energy efficiency of 70.4% at 80 oC and 50 mA cm‐2. Additionally, the Zn‐H2O system can be charged using renewable energy to produce H2 on demand and runs for 600 cycles only sacrificing 3.76% energy efficiency. DFT calculations reveal that the desorption of H* on Raney‐Ni (‐0.30 eV) is closer to zero compared with that on Zn (‐0.87 eV), indicating a faster desorption of H* at low overpotential. Further, a 24 Ah electrolyzer is demonstrated to produce H2 with a net energy efficiency of 65.5%, which holds promise for its real application.

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Catalyze hydrolysis reaction for hydrogen generation by Mg/Mg2Ca nanolamellar structure in Mg–Ca alloys

Cited by 14 publications

References 51 publications

Microstructural Transformation and Hydrogen Generation Performance of Magnesium Scrap Ball Milled with Devarda’s Alloy

Microstructural Transformation and Hydrogen Generation Performance of Magnesium Scrap Ball Milled with Devarda’s Alloy

Rechargeable Zn‐H₂O hydrolysis battery for hydrogen storage and production

Rechargeable Zn‐H₂O hydrolysis battery for hydrogen storage and production

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Catalyze hydrolysis reaction for hydrogen generation by Mg/Mg2Ca nanolamellar structure in Mg–Ca alloys

Cited by 14 publications

References 51 publications

Microstructural Transformation and Hydrogen Generation Performance of Magnesium Scrap Ball Milled with Devarda’s Alloy

Microstructural Transformation and Hydrogen Generation Performance of Magnesium Scrap Ball Milled with Devarda’s Alloy

Rechargeable Zn‐H2O hydrolysis battery for hydrogen storage and production

Rechargeable Zn‐H2O hydrolysis battery for hydrogen storage and production

Contact Info

Product

Resources

About

Rechargeable Zn‐H₂O hydrolysis battery for hydrogen storage and production

Rechargeable Zn‐H₂O hydrolysis battery for hydrogen storage and production