Study on degradation of filamentary Ni catalyst on hydrolysis of sodium borohydride

Kim, Jin-Ho; Kim, Ki-Tae; Kang, Yong‐Mook; Kim, Hyun‐Seok; Song, Min‐Sang; Lee, Yong-Ju; Lee, Paul S.; Jai-Young, Lee

doi:10.1016/j.jallcom.2004.02.009

Cited by 93 publications

(49 citation statements)

References 12 publications

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“…Though very active and almost-100% hydrogen selective, the Pt-, Rh-and Ir-containing systems were found not to be stable after the first cycle because of nickel surface enrichment, explained by borate-induced segregation [47,52]. Nickel, like cobalt, strongly adsorbs borates via M-O-B bonds, leading to the catalyst deactivation [54][55][56]. However, the presence of both Ni and the noble metal is essential and would be the optimum conditions to activate the bonds of the N2H4 moiety of hydrazine borane [52].…”

Section: Hydrolysis Of the Bh3 Group And Dehydrogenation Of The N2h4 mentioning

confidence: 99%

Hydrazine Borane and Hydrazinidoboranes as Chemical Hydrogen Storage Materials

Moury

Demirci

2015

Energies

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Abstract:Hydrazine borane N2H4BH3 and alkali derivatives (i.e., lithium, sodium and potassium hydrazinidoboranes MN2H3BH3 with M = Li, Na and K) have been considered as potential chemical hydrogen storage materials. They belong to the family of boron-and nitrogen-based materials and the present article aims at providing a timely review while focusing on fundamentals so that their effective potential in the field could be appreciated. It stands out that, on the one hand, hydrazine borane, in aqueous solution, would be suitable for full dehydrogenation in hydrolytic conditions; the most attractive feature is the possibility to dehydrogenate, in addition to the BH3 group, the N2H4 moiety in the presence of an active and selective metal-based catalyst but for which further improvements are still necessary. However, the thermolytic dehydrogenation of hydrazine borane should be avoided because of the evolution of significant amounts of hydrazine and the formation of a shock-sensitive solid residue upon heating at >300 °C. On the other hand, the alkali hydrazinidoboranes, obtained by reaction of hydrazine borane with alkali hydrides, would be more suitable to thermolytic dehydrogenation, with improved properties in comparison to the parent borane. All of these aspects are surveyed herein and put into perspective.

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Section: Hydrolysis Of the Bh3 Group And Dehydrogenation Of The N2h4 mentioning

confidence: 99%

Hydrazine Borane and Hydrazinidoboranes as Chemical Hydrogen Storage Materials

Moury

Demirci

2015

Energies

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“…Kim et al [96] tested the durability of a filamentary Ni catalyst over 200 cycles. It was observed that 76% of the initial H 2 generation remained at 200 cycles.…”

Section: Long-life Testsmentioning

confidence: 99%

“…Özkar and coworkers [66,67,70] applied a procedure similar to that applied by Kim et al [96] for testing the durability of their catalysts. At 25°C and for a borohydride solution storing about 0.1 wt.-% hydrogen, Ru [66], Ni [70] and Ni [67] nanoclusters provided 5,170, 1,450 (over 240 min) and 1,200 (over 180 min) total turnovers in the hydrolysis of NaBH 4 before deactivation, respectively.…”

Section: Long-life Testsmentioning

confidence: 99%

Sodium Borohydride Hydrolysis as Hydrogen Generator: Issues, State of the Art and Applicability Upstream from a Fuel Cell

et al. 2010

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Today there is a consensus regarding the potential of NaBH4 as a good candidate for hydrogen storage and release via hydrolysis reaction, especially for mobile, portable and niche applications. However as gone through in the present paper two main issues, which are the most investigated throughout the open literature, still avoid NaBH4 to be competitive. The first one is water handling. The second one is the catalytic material used to accelerate the hydrolysis reaction. Both issues are objects of great attentions as it can be noticed throughout the open literature. This review presents and discusses the various strategies which were considered until now by many studies to manage water and to improve catalysts performances (reactivity and durability). Published studies show real improvements and much more efforts might lead to significant overhangs. Nevertheless, the results show that we are still far from envisaging short‐term commercialisation.

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“…The catalyst durability issue of SB hydrolysis has been reported previously (Kim et al 2004;Kim 2009;Kojima et al 2004;Liu and Li 2009;Zhang et al 2006 been discussed. Among those challenges, they noted that dissolution of the catalyst and precipitation of hydrated borates on the catalyst are common challenges when using alkaline SB.…”

Section: Resultsmentioning

confidence: 95%

An on-demand microfluidic hydrogen generator with self-regulated gas generation and self-circulated reactant exchange with a rechargeable reservoir

Zhu

Kroodsma

Yeom

et al. 2011

Microfluid Nanofluid

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This article introduces an on-demand microfluidic hydrogen generator that can be integrated with a microproton exchange membrane (PEM) fuel cell. The catalytic reaction, reactant circulation, gas/liquid separation, and autonomous control functionalities are all integrated into a single microfluidic device. It generates hydrated hydrogen gas from an aqueous ammonia borane solution which is circulated and exchanged between the microfluidic reactor and a rechargeable fuel reservoir without any parasitic power consumption. Ammonia borane is chosen instead of sodium borohydride because of its faster hydrogen generation rate, higher hydrogen storage capability, stability, and better catalyst durability. The self-circulation of the ammonia borane solution was achieved using directional growth and selective venting of hydrogen bubbles in micro-channels, which leads to agitation and addition of fresh solution without consumption of electrical power. The self-regulation mechanism ensures that hydrogen can be supplied to a fuel cell according to the exact demand of the current output of the fuel cell. The circulation flow rate of ammonia borane solution is also automatically regulated by the venting rate of hydrogen at the gas outlet. Design, fabrication, and testing results of a prototype system are described. The hydrogen generator is capable of generating hydrogen gas at a maximum rate of 0.6 ml/min (2.1 ml/min cm 2 ) and circulating aqueous ammonia borane at a maximum flow rate of *15.7 ll/min. The device has also been connected with a micro-PEM fuel cell to demonstrate the feasibility of its practical applications in a high-impedance system.

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Study on degradation of filamentary Ni catalyst on hydrolysis of sodium borohydride

Cited by 93 publications

References 12 publications

Hydrazine Borane and Hydrazinidoboranes as Chemical Hydrogen Storage Materials

Hydrazine Borane and Hydrazinidoboranes as Chemical Hydrogen Storage Materials

Sodium Borohydride Hydrolysis as Hydrogen Generator: Issues, State of the Art and Applicability Upstream from a Fuel Cell

An on-demand microfluidic hydrogen generator with self-regulated gas generation and self-circulated reactant exchange with a rechargeable reservoir

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