Kinetic Assessment of Catalysts for the Methanolysis of Sodium Borohydride for Hydrogen Generation

Lo, Chen-Chia; Karan, Kunal; Davis, Boyd

doi:10.1021/ie8009186

Cited by 80 publications

(25 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The E a value of the methanolysis reaction of NaBH 4 catalyzed by p‐PEI microgels is lower than that of some hydrolysis reactions of NaBH 4 catalyzed by PEI‐M composites and other hydrolysis of NaBH 4 reactions . The methanolysis of NaBH 4 reaction catalyzed by p‐PEI microgels with 24.0 ± 0.4 kJ/mol is also lower than some of the metal‐catalyzed alcoholysis reactions reported in the literature .…”

Section: Resultsmentioning

confidence: 60%

“…Interestingly, there is almost no report of low‐temperature hydrolysis of NaBH 4 that may have significant impact on real‐time applications in automobiles and portable appliances . Therefore, alcoholysis studies of NaBH 4 have recently been reported as they offer additional advantages such as fast production of H 2 , easily regeneration of reaction products to NaBH 4 , and the elimination of freezing problems that are associated by the use of water. Various alcohols such as ethanol , 1,2 ethane diol , glycerol , and methanol have been used for the H 2 production from NaBH 4 .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Very fast H₂production from the methanolysis of NaBH₄by metal-free poly(ethylene imine) microgel catalysts

Şahiner

Demirci

2016

Int. J. Energy Res.

View full text Add to dashboard Cite

Summary The polyethyleneimine (PEI) microgels prepared via microemulsion polymerization are protonated by hydrochloric acid treatment (p‐PEI) and quaternized (q‐PEI) via modification reaction with methyl iodide and with bromo alkanes of different alkyl chain lengths such as 1‐bromoethane, 1‐bromobutane, 1‐bromohexane, and 1‐bromooctane. The bare p‐PEI and q‐PEI microgels are used as catalysts directly without any metal nanoparticles for the methanolysis reaction of sodium borohydride (NaBH4). Various parameters such as the protonation/quaternization reaction on PEI microgels, the amount of catalyst, the amount of NaBH4, and temperature are investigated for their effects on the hydrogen (H2) production rate. The reaction of self‐methanolysis of NaBH4 finishes in about 32.5 min, whereas the bare PEI microgel as catalyst finishes the methanolysis of NaBH4 in 22 min. Surprisingly, it is found that when the protonated PEI microgels are used as catalyst, the same methanolysis of NaBH4 is finished in 1.5 min. The highest H2 generation rate value is observed for protonated PEI microgels (10 mg) with 8013 mL of H2/(g of catalyst.min) for the methanolysis of NaBH4. Moreover, activation parameters are also calculated with activation energy value of 23.7 kJ/mol, enthalpy 20.9 kJ/mol, and entropy −158 J/K.mol. Copyright © 2016 John Wiley & Sons, Ltd.

show abstract

Section: Resultsmentioning

confidence: 60%

Section: Introductionmentioning

confidence: 99%

Very fast H₂production from the methanolysis of NaBH₄by metal-free poly(ethylene imine) microgel catalysts

Şahiner

Demirci

2016

Int. J. Energy Res.

View full text Add to dashboard Cite

show abstract

“…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

View full text Add to dashboard Cite

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]...

show abstract

“…The reports are based on the amount of hydrogen released when different alcohols and the catalysts have been used. The efficacy of metal chlorides and platinum-coated lithium cobalt oxide as catalysts for the methanolysis of sodium borohydride over 45 to À20 C was investigated by Lo et al [20]. Most of the studies in the literature have been carried out to study the hydrolysis of stabilized sodium borohydride solutions in the presence of the catalyst.…”

Section: Introductionmentioning

confidence: 99%

Hydrogen production by alcoholysis of sodium borohydride

Ramya¹,

Dhathathreyan²,

Sreenivas³

et al. 2013

Int. J. Energy Res.

View full text Add to dashboard Cite

SUMMARY Alcoholysis of sodium borohydride offers advantages due to reduction in number of steps for recycling of sodium borohydride, elimination of freezing problems that are associated with the use of water, fast generation of hydrogen, etc. Methanol was used to liberate hydrogen from sodium borohydride. The influence of the amount of solvent, substrate concentration, temperature and catalyst on the kinetics of alcoholysis reaction in non‐stabilized sodium borohydride has been examined in the present study. The reaction was found to be first order with respect to substrate concentration and zero order with respect to solvent concentration. Effect of soluble metal salts, metal powder and metal boride as catalysts on hydrogen generation rate has also been investigated. It was found that NiCl2, Ni2B and RuCl3 were effective catalysts and hydrogen generation proceeds with high efficiency in the presence of these catalysts. Copyright © 2013 John Wiley & Sons, Ltd.

show abstract

Kinetic Assessment of Catalysts for the Methanolysis of Sodium Borohydride for Hydrogen Generation

Cited by 80 publications

References 30 publications

Very fast H₂production from the methanolysis of NaBH₄by metal-free poly(ethylene imine) microgel catalysts

Very fast H₂production from the methanolysis of NaBH₄by metal-free poly(ethylene imine) microgel catalysts

Hydrogen production through sodium borohydride ethanolysis

Hydrogen production by alcoholysis of sodium borohydride

Contact Info

Product

Resources

About

Kinetic Assessment of Catalysts for the Methanolysis of Sodium Borohydride for Hydrogen Generation

Cited by 80 publications

References 30 publications

Very fast H2production from the methanolysis of NaBH4by metal-free poly(ethylene imine) microgel catalysts

Very fast H2production from the methanolysis of NaBH4by metal-free poly(ethylene imine) microgel catalysts

Hydrogen production through sodium borohydride ethanolysis

Hydrogen production by alcoholysis of sodium borohydride

Contact Info

Product

Resources

About

Very fast H₂production from the methanolysis of NaBH₄by metal-free poly(ethylene imine) microgel catalysts

Very fast H₂production from the methanolysis of NaBH₄by metal-free poly(ethylene imine) microgel catalysts