The Role of Ionic Liquids in Hydrogen Storage

Sahler, Sebastian; Sturm, Sebastian; Kessler, M.; Prechtl, Martin H. G.

doi:10.1002/chem.201304868

Cited by 24 publications

(20 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…They act merely as a polar medium for the stabilization of the intermediate by lowering the activation energies of dehydrogenation. 16 In addition to possible carbene formation from imidazolium cations, which can exert a strong effect on the hydrogen yield, the basicity of anions also inuences the yield. The primary criterion for selecting an IL for EDAB was higher solubility.…”

Section: Selection Of Ilsmentioning

confidence: 99%

See 1 more Smart Citation

Quantum chemical and experimental insights for the ionic liquid facilitated thermal dehydrogenation of ethylene diamine bisborane

et al. 2015

View full text Add to dashboard Cite

The current work reports the judicial selection and subsequent dehydrogenation reaction with ionic liquid (IL) facilitated ethylene diamine bisborane (EDAB). Quantum chemical based COSMO-SAC (COnductor like Screening MOdel Segment Activity Coefficient) model was initially used to screen the ILs as available from Sigma Aldrich. LUMO-HOMO calculation was then performed to analyze the stability of EDAB/IL complexes. The molecular modeling studies converged on the two ILs, namely 1-ethyl-3-methyl imidazolium acetate ([EMIM][OAc]) and 1-butyl-3-methyl imidazolium acetate ([BMIM][OAc]), which were subsequently chosen for the dehydrogenation experiments. The thermal dehydrogenation of EDAB was carried out at 95 C and 105 C under vacuum so as to prevent generation of oxygen moieties. A total of 3.96 and 3.52 equivalents of hydrogen were released from the desorption of EDAB/[BMIM][OAc] and EDAB/[EMIM][OAc], respectively, at 105 C. The purity of released gas was confirmed by gas chromatographic analysis, while the catalytic activity of ILs was confirmed by 1 H NMR characterization of pure EDAB, ILs and EDAB/IL complexes both before and after the reaction. 11 B NMR analysis confirms the presence of trigonal boron (sp 2 ) BH 2 group as the only hydrogen containing boron moiety in dehydrogenated EDAB. Further, the two-stage release mechanism of EDAB was also verified by thermogravimetric analysis. High resolution mass spectrometry was able to detect the mass of cyclic repeat units in the polymeric chain containing an sp 2 BH 2 group. † Electronic supplementary information (ESI) available: The COSMO-SAC parameters and the sigma proles of EDAB, imidazolium cations and acetate anions. Further it also depicts the HOMO-LUMO energy gap of EDAB, [EMIM] [OAc] and [BMIM][OAc]. SeeFig. 8 Plot for 11 B NMR. (a) EDAB/[BMIM][OAc] before reaction, (b) EDAB/[BMIM][OAc] after reaction.This journal is

show abstract

Section: Selection Of Ilsmentioning

confidence: 99%

“…16 We conducted HR-MS analysis in the positive APCI mode and the spectra is plotted in Fig. It should be noted that the amount of released hydrogen cannot be explained by the degree of polymerization.…”

Section: Hr-msmentioning

confidence: 99%

Quantum chemical and experimental insights for the ionic liquid facilitated thermal dehydrogenation of ethylene diamine bisborane

et al. 2015

View full text Add to dashboard Cite

show abstract

“…Since the pioneering work of Bluhm et al of employing IL as dual role of solvent and catalyst, several attempts are being made to use IL as viable scaffold and hydrogen production from amine borane. However, a lot of effort has been dedicated towards imidazolium class of IL because of its ability to accelerate the dehydrogenation in combination with basic anions . Following the Bluhm's work, Himmelberger et al proposed detail reaction mechanism of AB/[BMIM][Cl] system and proved the presence of DADB, PAB, and polyborazylene on the course of dehydrogenation.…”

Section: Resultsmentioning

confidence: 99%

Effect of thiocyanate‐based ionic liquids on the dehydrogenation of amine boranes: Experimental and molecular modeling studies

Kundu

Chakma

Pugazhenthi

et al. 2019

Asia-Pacific J Chem Eng

View full text Add to dashboard Cite

The present investigation reports the effect of thiocyanate-based ionic liquid (IL) on the thermal dehydrogenation of amine boranes. Fifteen ILs based on thiocyanate anion comprising cations from imidazolium, pyrrolidinium, and ammonium family were screened by a priori prediction of infinite dilution activity coefficient using the quantum chemical-based conductor-like screening model segment activity coefficient method. The IL with the highest predicted solubility of amine boranes converged to 1-ethyl-3-methylimidazolium thiocyanate ([EMIM] [SCN]) that was then used for the dehydrogenation reaction. In the IL medium, ammonia borane (AB) and ethylene diamine bisborane (EDAB) were found to produce~1.64 equivalent of hydrogen with an induction period of 60 min and~2.37 equivalent of hydrogen having an induction period of 30 min, respectively. It was observed that the mixture of AB and EDAB in [EMIM][SCN] produced prolonged induction period of 210 min. After 240 min, the mixed amine boranes only produce 0.43 equivalent of H 2 . To elucidate this slow dynamics, Density Functional Theory (DFT) optimized geometries followed by the natural bond orbital analysis revealed the formation of hydrogen bond between IL and amine borane moiety. Further, the presence of the stronger dihydrogen bond among the protic and hydridic hydrogens was also observed in AB + EDAB/[EMIM][SCN] system, resulting in longer induction period for dehydrogenation. KEYWORDS amine borane, boron NMR, natural bond orbital, thiocyanate ionic liquid

show abstract

“…[260] The hydrogen release of ammonia boranes in ILs was also affected by the temperature, [258,259] ammonia borane/IL weight ratio, [259] IL structure and properties, [260,261] and type of ammonia boranes. [262,263] In addition to their use as promoting solvents for hydrogen release, the potential of ILs themselves as efficient chemical hydrogen-storage materials has also been explored by exploiting the unique features of ILs, such as low vapor pressure and structure tunability. [264][265][266] Changing the cross-linking group from methacrylate to vinyl was found to dramatically reduce the tensile modulus and results in brittle films.…”

Section: Hydrogen-storage Materialsmentioning

confidence: 99%

Beyond solvents and electrolytes: Ionic liquids-based advanced functional materials

Zhang

et al. 2016

Progress in Materials Science

136

View full text Add to dashboard Cite

Instead of being seen as alternative solvents and electrolytes for organic reactions, catalysis, separation, electrochemistry, and so on, ionic liquids (ILs) consisting of discrete cations and anions have recently emerged as versatile building blocks for advanced functional materials. A number of functional ILs and IL-containing composite materials have been realized by either chemical modification (covalent functionalization or ion-exchange metathesis) or physical integration of ILs and traditional materials. The unique structure and behavior of ILs as a platform not only provides additional opportunities to adjust the physicochemical properties of these ionic materials for task-specific applications, but also offers other attractive features such as intrinsic ionic conductivity and high thermal, chemical, and electrochemical stability. These soft materials combine the favorable features of ILs and the original chemistries of the functional groups or materials; some even possess unexpected functions resulting from synergetic interaction between these two components. Materialization of ILs is truly a novel, promising research direction for both IL chemistry and materials science. In this article, we review recent advances in IL-based functional materials, focusing on smart and sensitive materials, optical materials, energetic materials, and IL/carbon hybrid materials.

show abstract

The Role of Ionic Liquids in Hydrogen Storage

Cited by 24 publications

References 43 publications

Quantum chemical and experimental insights for the ionic liquid facilitated thermal dehydrogenation of ethylene diamine bisborane

Quantum chemical and experimental insights for the ionic liquid facilitated thermal dehydrogenation of ethylene diamine bisborane

Effect of thiocyanate‐based ionic liquids on the dehydrogenation of amine boranes: Experimental and molecular modeling studies

Beyond solvents and electrolytes: Ionic liquids-based advanced functional materials

Contact Info

Product

Resources

About