Enhanced hydrogen generation by methanolysis of sodium borohydride in the presence of phosphorus modified boehmite

Xu, Dongyan; Cheng, Fei; Zhao, Lin

doi:10.1016/j.fuel.2014.05.071

Cited by 43 publications

(14 citation statements)

References 31 publications

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“…As an alternative to the use of water, alcohols have been proposed as efficient solvolytic agents. In particular, methanolysis (reaction of SB with methanol, CH 3 OH) has been reported (2) as advantageous because its high potential gravimetric hydrogen density (GHD 4.9 wt%), the possibility of sub-zero hydrogen generation, and the fact that the reaction product (NaB(OCH 3 ) 4 ) does not have tendency to plug the reactors as occurs with NaBO 2 [13][14][15][16][17][18][19][20]. At present, some energy technologies that aim at using methanol are under development.…”

Section: Nabh 4 + 2 H 2 O → 4h 2 + Nabo 2 (1)mentioning

confidence: 99%

Hydrogen production through sodium borohydride ethanolysis

Arzac

Fernández

2015

International Journal of Hydrogen Energy

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In this work, sodium borohydride (SB) ethanolysis was explored for the first time as a method to generate hydrogen for Polymer Exchange Membrane Fuel Cells. Ethanolysis by-product was characterized by Fourier Transform Infrared Spectroscopy, X-Ray Diffraction, and Nuclear Magnetic Resonance. Metal and acid catalysts were tested. RuCl 3 3H 2 O was the best metal catalyst. Acetic acid was selected for the study because of its effectiveness, low cost and relative greenness. The maximum gravimetric hydrogen density obtained was 2.1 % wt. The addition of water produces an increase in hydrogen generation rate and a decrease in conversion. The use of ethanol-methanol mixtures produces an increase in reaction rates in absence of catalyst. As a proof of concept the reaction was performed in a small reactor which operates by the addition of ethanolic acetic acid solutions to solid SB (in the form of granules). The reactor produces stable and constant hydrogen generation in the range of 20-80ml.min -1 during 1h at constant temperature (around 27-35ºC). 1.IntroductionAt present, hydrogen is being considered as a clean energy carrier that may contribute to reduce the dependence on fossil fuels and the greenhouse effect produced by their use.Hydrogen has a high energy density (39.4 kWh.kg -1 while for hydrocarbons is 13.1kWh.kg -1 ) and its reaction with oxygen produces energy and water as only byproduct. However, the use of hydrogen faces many challenges related to clean production, transport, storage and combustion (direct or in a fuel cell). Regarding hydrogen storage, great efforts have been made in these years to develop suitable materials with high gravimetric and volumetric density. Boron based hydrides are very attractive because of the combination of their lightweight and high hydrogen content [1-3]. Among them, sodium borohydride (NaBH 4 , SB) is the most studied because of its stability in dry air and safe handling [4][5][6]. Although it is no longer recommended for vehicular use, it still has potential for portable and niche applications [5]. SB produces hydrogen through catalysed solvolysis reactions. Sodium borohydride hydrolysis (reaction 1) is the most studied solvolytic reaction and has a potential gravimetric hydrogen density (GHD) around 10.8 % wt. Reaction (1) has demonstrated to be versatile enough to produce hydrogen in reactors in a wide range of rates (0-6L.min -1 ) and with interesting effective GHDs (up to 9 wt% when employing solid SB and around 4 wt% when using stabilized SB solutions) [4][5][6][7][8][9][10][11][12]. NaBH 4 + 2 H 2 O → 4H 2 + NaBO 2 (1)As an alternative to the use of water, alcohols have been proposed as efficient solvolytic agents. In particular, methanolysis (reaction of SB with methanol, CH 3 OH) has been reported (2) as advantageous because its high potential gravimetric hydrogen density (GHD 4.9 wt%), the possibility of sub-zero hydrogen generation, and the fact that the reaction product (NaB(OCH 3 ) 4 ) does not have tendency to plug the reactors as occurs with NaBO 2 [13][14]...

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Section: Nabh 4 + 2 H 2 O → 4h 2 + Nabo 2 (1)mentioning

confidence: 99%

Hydrogen production through sodium borohydride ethanolysis

Arzac

Fernández

2015

International Journal of Hydrogen Energy

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“…H 2 can also be stored in hydride forms with many metals such as sodium borohydride (NaBH 4 ), lithium borohydride (LiBH 4 ), potassium borohydride (KBH 4 ), aluminum borohydride, and even as ammonium borane (NH 3 BH 3 ) . Due to the economical and handling concerns, NaBH 4 with high H 2 content, 10.8 wt% is highly preferred . To release H 2 from NaBH 4 , various solvolysis reactions are required in the presence of a pertinent catalyst.…”

Section: Introductionmentioning

confidence: 99%

“…Alcoholysis of NaBH 4 is an important and convenient reaction to generate H 2 in the presence of suitable catalysts . This reaction can offer numerous advantages such as faster reaction kinetics, lower Ea, and ability to generate H 2 at subzero temperatures even in the presence of metal‐free catalysts with readily regeneration capabilities . Amidst the solvents, methanol provides some accountable advantages over hydrolysis, as H 2 release from NaBH 4 methanolysis can be conveniently run at low temperatures (T < 0°C) efficiently, eg, −20°C, abiding by the following equation:

{NaBH}_{4} + {4CH}_{3} OH \to NaB {({OCH}_{3})}_{4} + {4H}_{2} .

…”

Section: Introductionmentioning

confidence: 99%

“…17 Due to the economical and handling concerns, NaBH 4 with high H 2 content, 10.8 wt% is highly preferred. 18 To release H 2 from NaBH 4 , various solvolysis reactions are required in the presence of a pertinent catalyst. The solvents such as water (hydrolysis) and alcohols (methanolysis, ethanolysis, etc) are the most convenient employed solvents.…”

Section: Introductionmentioning

confidence: 99%

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Surface‐modified carbon black derived from used car tires as alternative, reusable, and regenerable catalysts for H ₂ release studies from sodium borohydride methanolysis

Ari

Sunol

et al. 2019

Int J Energy Res

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Summary Carbon black (CB) obtained from used car tire rubbers were treated with concentrated sulfuric and nitric acids. The oxidized CB (CB‐COO‐Na+) is subsequently modified with epichlorohydrin (ECH) and amines including polyethylene imine (PEI). These modified CBs such as CB‐PEI are used as metal‐free catalysts in methanolysis of sodium borohydride (NaBH4) to produce hydrogen. The hydrogen generation rate (HGR) of 3089 ± 44.69 mL.min‐1.g‐1 is accomplished at room temperature with CB‐PEI‐hydrochloric acid (HCl) catalyst. The resulting activation energy of 34.7 kJ/mol for the temperature range of −20°C to +30°C compares favorably to most of alternative catalysts reported in literature while reaction catalyzing capabilities of CB‐PEI‐HCl particles extend to the subzero temperature range (−20°C‐0°C). The reuse and regeneration studies conducted for the CB‐PEI‐HCl catalyst showed that these catalysts do provide complete conversion at every use up to five consecutive runs and retain 50 ± 2.5% of the original hydrogen generation rate at the fifth consecutive reuse. The CBs‐based catalysts are fully regenerated with HCl treatment.

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“…Typical examples of such reactions are methanolysis (i.e., ROH=CH 3 OH) of sodium borohydride186 or ammonia borane187 and glycolysis of sodium borohydride 188. The use of methanol as a solvolytic agent is detrimental to the theoretical gravimetric hydrogen‐storage capacity of the couple NaBH 4 –solvent if methanol is compared to water (i.e., 4.8 vs. 7.3 wt % H 2 ), but methanolysis has two advantages over hydrolysis.…”

Section: Hydrogen Carriersmentioning

confidence: 99%

Cyclic Dehydrogenation–(Re)Hydrogenation with Hydrogen‐Storage Materials: An Overview

2015

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Hydrogen‐storage materials (HSMs) have especially revolutionized the field of “hydrogen storage” by offering a relatively safe storage alternative and high gravimetric hydrogen density. However, a critical challenge is storage reversibility. This is the central tenet of the present article, which discusses ways to close the hydrogen cycle with solid‐ and liquid‐phase HSMs. A distinction between the different HSMs is made on the basis of the approach under which they can be rehydrogenated; this led to the proposition of distribution in three categories: one, materials allowing reversible storage of H2; two, hydrogen carriers for which the byproducts must be recycled; three, sustainable hydrogen carriers with which the hydrogen cycle is considered as being byproduct free. From our analysis, supported by many examples, it seems that the hydrogen cycle can be closed with all of the HSMs discussed herein and that the dehydrogenation/rehydrogenation paths depend on their nature.

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Enhanced hydrogen generation by methanolysis of sodium borohydride in the presence of phosphorus modified boehmite

Cited by 43 publications

References 31 publications

Hydrogen production through sodium borohydride ethanolysis

Hydrogen production through sodium borohydride ethanolysis

Surface‐modified carbon black derived from used car tires as alternative, reusable, and regenerable catalysts for H ₂ release studies from sodium borohydride methanolysis

Cyclic Dehydrogenation–(Re)Hydrogenation with Hydrogen‐Storage Materials: An Overview

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Enhanced hydrogen generation by methanolysis of sodium borohydride in the presence of phosphorus modified boehmite

Cited by 43 publications

References 31 publications

Hydrogen production through sodium borohydride ethanolysis

Hydrogen production through sodium borohydride ethanolysis

Surface‐modified carbon black derived from used car tires as alternative, reusable, and regenerable catalysts for H 2 release studies from sodium borohydride methanolysis

Cyclic Dehydrogenation–(Re)Hydrogenation with Hydrogen‐Storage Materials: An Overview

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Surface‐modified carbon black derived from used car tires as alternative, reusable, and regenerable catalysts for H ₂ release studies from sodium borohydride methanolysis