Closed loops for hydrogen storage: Hydrolysis and regeneration of metal borohydrides

Zhu, Yongyang; Li, Jianding; Yang, Limei; Huang, Zhenguo; Yang, Xusheng; Zhou, Qing; Tang, Renheng; Shen, Shaoyang; Ouyang, Liuzhang

doi:10.1016/j.jpowsour.2023.232833

“…reported that NaBO 2 in aqueous solution reacts with CO 2 in air forming Na 2 B 4 O 7 ⋅ 10H 2 O and Na 2 CO 3 according to the following reaction: 4NaBO 2 ⋅ xH 2 O+CO 2 +(10‐4x)H 2 O→Na 2 B 4 O 7 ⋅ 10H 2 O+Na 2 CO 3 , where Na 2 B 4 O 7 ⋅ 10H 2 O is the main constituent of the naturally abundant borax mineral [76] . NaBH 4 can be produced by the reaction of Na 2 B 4 O 7 ⋅ 10H 2 O with metal hydrides (e.g., MgH 2 , NiH 2 ), or metal and H 2 at the designed conditions [13,76,77] . As NaBH 4 is a key material in AB synthesis, NaBH 4 and NH 4 Cl were combined to regenerate NH 4 BH 4 .…”

Section: Resultsmentioning

confidence: 99%

Silica Confinement for Stable and Magnetic Co−Cu Alloy Nanoparticles in Nitrogen‐Doped Carbon for Enhanced Hydrogen Evolution

Wan,

Li,

Wang

et al. 2024

Angewandte Chemie

3

0

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Ammonia borane (AB) with 19.6 wt.% H2 content is widely considered a safe and efficient medium for H2 storage and release. Co‐based nanocatalysts present strong contenders for replacing precious metal‐based catalysts in AB hydrolysis due to their high activity and cost‐effectiveness. However, precisely adjusting the active centers and surface properties of Co‐based nanomaterials to enhance their activity, as well as suppressing the migration and loss of metal atoms to improve their stability, presents many challenges. In this study, mesoporous‐silica‐confined bimetallic Co‐Cu nanoparticles embedded in nitrogen‐doped carbon (CoxCu1‐x@NC@mSiO2) were synthesized using a facile mSiO2‐confined thermal pyrolysis strategy. The obtained product, an optimized Co0.8Cu0.2@NC@mSiO2 catalyst, exhibits enhanced performance with a turnover frequency of 240.9 molH2∙molmetal∙min‐1 for AB hydrolysis at 298 K, surpassing most noble‐metal‐free catalysts. Moreover, Co0.8Cu0.2@NC@mSiO2 demonstrated magnetic recyclability and extraordinary stability, with a negligible decline of only 0.8% over 30 cycles of use. This enhanced performance was attributed to the synergistic effect between Co and Cu, as well as silica confinement. This work proposes a promising method for constructing noble‐metal‐free catalysts for AB hydrolysis.

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“…[76] NaBH 4 can be produced by the reaction of Na 2 B 4 O 7 • 10H 2 O with metal hydrides (e.g., MgH 2 , NiH 2 ), or metal and H 2 at the designed conditions. [13,76,77] As NaBH 4 is a key material in AB synthesis, NaBH 4 and NH 4 Cl were combined to regenerate NH 4 BH 4 . Finally, one molecule of H 2 was removed using reasonable measures to obtain regenerated NH 3 BH 3 .…”

Section: Angewandte Chemiementioning

confidence: 99%

Silica Confinement for Stable and Magnetic Co−Cu Alloy Nanoparticles in Nitrogen‐Doped Carbon for Enhanced Hydrogen Evolution

Wan,

Li,

Wang

et al. 2024

Angew Chem Int Ed

12

0

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Ammonia borane (AB) with 19.6 wt.% H2 content is widely considered a safe and efficient medium for H2 storage and release. Co‐based nanocatalysts present strong contenders for replacing precious metal‐based catalysts in AB hydrolysis due to their high activity and cost‐effectiveness. However, precisely adjusting the active centers and surface properties of Co‐based nanomaterials to enhance their activity, as well as suppressing the migration and loss of metal atoms to improve their stability, presents many challenges. In this study, mesoporous‐silica‐confined bimetallic Co‐Cu nanoparticles embedded in nitrogen‐doped carbon (CoxCu1‐x@NC@mSiO2) were synthesized using a facile mSiO2‐confined thermal pyrolysis strategy. The obtained product, an optimized Co0.8Cu0.2@NC@mSiO2 catalyst, exhibits enhanced performance with a turnover frequency of 240.9 molH2∙molmetal∙min‐1 for AB hydrolysis at 298 K, surpassing most noble‐metal‐free catalysts. Moreover, Co0.8Cu0.2@NC@mSiO2 demonstrated magnetic recyclability and extraordinary stability, with a negligible decline of only 0.8% over 30 cycles of use. This enhanced performance was attributed to the synergistic effect between Co and Cu, as well as silica confinement. This work proposes a promising method for constructing noble‐metal‐free catalysts for AB hydrolysis.

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“…Additionally, this includes gas manifolds (6), overpressure safety valves (7), pressure sensor (8), and hydrogen purifier (9) which removes mist and water vapour from hydrogen released in the reactor (1) when the acid solution is supplied thereto via the valve (4). The pressurised hydrogen fills the gas cylinder (11) connected to the system by a shut-off valve (10).…”

Section: Generation Of Compressed Hydrogen By Hydrolysis Of Mg or Mgh...mentioning

confidence: 99%

“…Along with various methods of reversible hydrogen storage based on physical processes (compression and liquefaction) and the use of hydrogen storage materials (high-surface area adsorbents, hydrides, liquid organic hydrogen carriers, etc.) [5], special attention has been recently paid to on-site (or on-board) hydrogen generation by the hydrolysis of various light-weight materials such as ammonia borane [6,7], sodium, lithium and magnesium borohydrides [8][9][10][11], aluminium [9,12] or alloys/composites on its basis [13], magnesium and magnesium alloys [9,[14][15][16][17][18], magnesium hydride [9,15,[19][20][21][22][23], and so on. These materials can undergo hydrolysis at near-ambient conditions, in alkaline, acidic, or neutral media, and frequently in the presence of a catalyst.…”

Section: Introductionmentioning

confidence: 99%

Tailoring of Hydrogen Generation by Hydrolysis of Magnesium Hydride in Organic Acids Solutions and Development of Generator of the Pressurised H2 Based on this Process

Lototskyy

¹

,

Davids

²

,

Sekgobela

³

et al. 2023

Inorganics

Self Cite

4

0

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Hydrolysis of light metals and hydrides can potentially be used for the generation of hydrogen on-board fuel cell vehicles, or, alternatively, for refilling their fuel tanks with H2 generated and pressurised without compressor on site, at near-ambient conditions. Implementation of this approach requires solution of several problems, including the possibility of controlling H2 release and avoiding thermal runaway. We have solved this problem by developing the apparatus for the controlled generation of pressurised H2 using hydrolysis of Mg or MgH2 in organic acid solutions. The development is based on the results of experimental studies of MgH2 hydrolysis in dilute aqueous solutions of acetic, citric, and oxalic acids. It was shown that the hydrogen yield approaches 100% with a fast hydrolysis rate when the molar ratio acid/MgH2 exceeds 0.9, 2.0, and 2.7 for the citric, oxalic, and acetic acids, respectively. In doing so, the pH of the reaction solutions after hydrolysis corresponds to 4.53, 2.11, and 4.28, accordingly, testifying to the buffer nature of the solutions “citric acid/magnesium citrate” and “acetic acid/magnesium acetate”. We also overview testing results of the developed apparatus where the process rate is effectively controlled by the control of the acid concentration in the hydrolysis reactor.

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Closed loops for hydrogen storage: Hydrolysis and regeneration of metal borohydrides

Cited by 18 publications

References 144 publications

Silica Confinement for Stable and Magnetic Co−Cu Alloy Nanoparticles in Nitrogen‐Doped Carbon for Enhanced Hydrogen Evolution

Silica Confinement for Stable and Magnetic Co−Cu Alloy Nanoparticles in Nitrogen‐Doped Carbon for Enhanced Hydrogen Evolution

Silica Confinement for Stable and Magnetic Co−Cu Alloy Nanoparticles in Nitrogen‐Doped Carbon for Enhanced Hydrogen Evolution

Tailoring of Hydrogen Generation by Hydrolysis of Magnesium Hydride in Organic Acids Solutions and Development of Generator of the Pressurised H2 Based on this Process

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