The effects of Ti-based additives on the kinetics and reactions in LiH/MgB2 hydrogen storage system

Zhang, Yao; Morin, François; Huot, Jacques

doi:10.1016/j.ijhydene.2011.01.135

Cited by 33 publications

(29 citation statements)

References 22 publications

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“…The reaction occurs at were mostly responsible for faster hydrogen desorption room temperature with the formation of LiCl. Similar result kinetics and only metallic titanium in LiHeMgB2 composite was observed in [16] for the interaction between LiBH4 and actively participates in both hydrogenation and dehydroge-TiCl4: nation process [28]. This is again the conÞrmation of more pronounced role of anion (the more electronegative atom in 4LiBH4 þ TiCl4 / Ti(BH4)3 þ 4LiCl þ 1/2B2H6 þ 1/2H2 (7) titanium additives) at association of atomic hydrogen than dissociation of molecular hydrogen.…”

supporting

confidence: 71%

“…valence; X is halogen) would be presented as follows: We suppose that chemically unreacted titanium additives (TiO2, TiN and TiC) could be the Òactive surface centersÓ, nLiBH4 þ MXn / nLiX þ M(BH4)n (4) where dissociation of molecular hydrogen under hydrogenation and association of atomic hydrogen under dehydrogenation can be accelerated. nLiX þ M(BH4)n / nLiX þ MBnþ 2nH2 (5) In recent work [28] the investigation of the effect of Ti, TiH2, TiB2, TiCl3, and TiF3 additives on the hydrogen sorption kinetics in LiH/MgB2 mixture has been done. There it was nLiX þ MBn þ 2nH2 / MXn þ nLiH þ nB þ 2nH2 (6) concluded that all these titanium additives effectively decrease the onset temperature of hydrogenation.…”

Section: Atr-ir Spectroscopy Of Milled and Hydrogenated Lihemgb 2 Ex mentioning

confidence: 99%

See 1 more Smart Citation

Enhanced hydrogen uptake/release in 2LiH–MgB 2 composite with titanium additives

Saldan

Campesi

Zavorotynska

et al. 2012

International Journal of Hydrogen Energy

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The influence of different titanium additives on hydrogen sorption in LiHeMgB 2 system has been investigated. For all the composites LiHeMgB 2 eX (X ¼ TiF 4 , TiO 2 , TiN, and TiC), prepared by ball-milling in molar ratios 2:1:0.1, Þve hydrogen uptake/release cycles were performed. In-situ synchrotron radiation powder X-ray diffraction (SR-PXD) and attenu-ated total reßection infrared spectroscopy (ATR-IR) have been used to characterize crystal phases developed during the hydrogen absorptionedesorption cycles.All the composites with the titanium additives displayed an improvement of reaction kinetics, especially during hydrogen desorption. The LiHeMgB 2 eTiO 2 system reached a storage of about 7.6 wt % H 2 in w1.8 h for absorption and w2.7 h for desorption. Using in-situ SR-PXD measurements, magnesium was detected as an intermediate phase during hydrogen desorption for all composites. In the composite with TiF 4 addition the formation of new phases (TiB 2 and LiF) were observed. Characteristic diffraction peaks of TiO 2 , TiN and TiC additives were always present during hydrogen absorptionedesorption. For all as-milled composites, ATR-IR spectra did not show any signals for borohydrides, while for all hydrogenated composites BeH stretching (2450e2150 cm 1 ) and BeH bending (1350e1000 cm 1 ) bands were exactly the same as for commercial LiBH 4 . IntroductionHydrogen can be one of the alternative energy carriers, which should replace the traditional fossil fuels in the near future. One of the promising materials for hydrogen mobile applica-tion which has been studied approximately for 10 years is LiBH 4 [1]. Having high gravimetric and volumetric hydrogen density, this material, though, exhibits unfavorable kinetics and thermodynamics for real application in fuel cells. Recently, it was found that LiBH 4 can be destabilized by the addition of MgH 2 , showing better decomposition kinetics with respect to the pure compound [2]. A detailed analysis of the reversible interaction between LiBH 4 and MgH 2 was made in [3] and can be summarized as follow: 2LiBH 4 þ MgH 2 4 2LiBH 4 þ Mg þ H 2 4 2LiH þ MgB 2 þ 4H 2 (1)The direct reactions (1) take place at w400 C. Opposite reactions, with simultaneous formation of LiBH 4 and MgH 2 under 50 bar of H 2 , was conÞrmed at the temperatures 250e300 C [3]. It was observed that suitable additives might decrease reaction temperatures and improve kinetics of Eq. (1). Experimental evidence of kinetic improvement for reversible middle-temperature Na, Li and Al based complex hydrides doped by titanium additives appeared in 1997 [4]. It has also been reported that the kinetic improvement of the reaction (1) was reached by addition of 1 mol% of TiF 3 [5]. The property enhancement arising upon this additive persists well in the subsequent hydrogen uptake/release cycles. Another prom-inent example of the additives effect was the composite LiBH 4 eMgH 2 eTi{OCH(CH 3 ) 2 } 4 mixed in molar ratio 2:1:0.1 [6]. After ball-milling TiO 2 anatase was found and during 1-st hydrogen desorptio...

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supporting

confidence: 71%

Section: Atr-ir Spectroscopy Of Milled and Hydrogenated Lihemgb 2 Ex mentioning

confidence: 99%

Enhanced hydrogen uptake/release in 2LiH–MgB 2 composite with titanium additives

Saldan

Campesi

Zavorotynska

et al. 2012

International Journal of Hydrogen Energy

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“…The superior effects of TiN@rGO on MgH 2 was investigated by our previous work [8]. Other literatures also confirmed the enhanced effects of Ti-based compounds on other typical hydrogen carriers [9][10][11][12][13][14][15][16]. However, despite the continuous reports about the enhanced effects of Ti-based materials on MgH 2 , a comparative study about their activities with different types of anions is still unknown.…”

Section: Introductionmentioning

confidence: 84%

Catalytic effects of different Ti-based materials on dehydrogenation performances of MgH2

Wang

Zhang

Wang

et al. 2015

Journal of Alloys and Compounds

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“…Based on this analysis, it is clear that the mutual destabilization effect between LiBH 4 and MgH 2 only occurs upon hydrogenation, but at relatively low temperatures (<413 • C) under equilibrium conditions. For the hydrogenation process carried out under dynamic conditions, the applied temperatures were usually in the range between 300 • C and 400 • C [33][34][35][36][37][38][56][57][58][59][60][61][62][63][64][65][66][67]; hence, the mutual destabilization effect was verified by a one-step curve of hydrogen uptake against time. However, for the dehydrogenation, the thermodynamics limits the behavior of Li-RHC to two main reaction steps, losing the benefit of the destabilization effect.…”

Section: Destabilized Mgh2-2libh4 System: Li-rhcmentioning

confidence: 99%

Tuning LiBH4 for Hydrogen Storage: Destabilization, Additive, and Nanoconfinement Approaches

et al. 2019

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Hydrogen technology has become essential to fulfill our mobile and stationary energy needs in a global low–carbon energy system. The non-renewability of fossil fuels and the increasing environmental problems caused by our fossil fuel–running economy have led to our efforts towards the application of hydrogen as an energy vector. However, the development of volumetric and gravimetric efficient hydrogen storage media is still to be addressed. LiBH4 is one of the most interesting media to store hydrogen as a compound due to its large gravimetric (18.5 wt.%) and volumetric (121 kgH2/m3) hydrogen densities. In this review, we focus on some of the main explored approaches to tune the thermodynamics and kinetics of LiBH4: (I) LiBH4 + MgH2 destabilized system, (II) metal and metal hydride added LiBH4, (III) destabilization of LiBH4 by rare-earth metal hydrides, and (IV) the nanoconfinement of LiBH4 and destabilized LiBH4 hydride systems. Thorough discussions about the reaction pathways, destabilizing and catalytic effects of metals and metal hydrides, novel synthesis processes of rare earth destabilizing agents, and all the essential aspects of nanoconfinement are led.

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The effects of Ti-based additives on the kinetics and reactions in LiH/MgB2 hydrogen storage system

Cited by 33 publications

References 22 publications

Enhanced hydrogen uptake/release in 2LiH–MgB 2 composite with titanium additives

Enhanced hydrogen uptake/release in 2LiH–MgB 2 composite with titanium additives

Catalytic effects of different Ti-based materials on dehydrogenation performances of MgH2

Tuning LiBH4 for Hydrogen Storage: Destabilization, Additive, and Nanoconfinement Approaches

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