43 research outputs found
Nanoconfined 2LiBH4eMgH2eTiCl3 in carbon aerogel scaffold for reversible hydrogen storage
No full textNanoconfinement of 2LiBH4–MgH2–TiCl3 in resorcinol–formaldehyde carbon aerogel scaffold (RF–CAS) for reversible hydrogen storage applications is proposed. RF–CAS is encapsulated with approximately 1.6 wt. % TiCl3 by solution impregnation technique, and it is further nanoconfined with bulk 2LiBH4–MgH2 via melt infiltration. Faster dehydrogenation kinetics is obtained after TiCl3 impregnation, for example, nanoconfined 2LiBH4–MgH2–TiCl3 requires ∼1 and 4.5 h, respectively, to release 95% of the total hydrogen content during the 1st and 2nd cycles, while nanoconfined 2LiBH4–MgH2 (∼2.5 and 7 h, respectively) and bulk material (∼23 and 22 h, respectively) take considerably longer. Moreover, 95–98.6% of the theoretical H2 storage capacity (3.6–3.75 wt. % H2) is reproduced after four hydrogen release and uptake cycles of the nanoconfined 2LiBH4–MgH2–TiCl3. The reversibility of this hydrogen storage material is confirmed by the formation of LiBH4 and MgH2 after rehydrogenation using FTIR and SR-PXD techniques, respectively.Fil: Gosalawit Utke, Rapee. Helmholtz-Zentrum Geesthacht; Alemania. Suranaree University of Technology; TailandiaFil: Milanese, Chiara. Universita degli Studi di Pavia; ItaliaFil: Javadian, Payam. University Aarhus; DinamarcaFil: Jepsen, Julian. Helmholtz-Zentrum Geesthacht; AlemaniaFil: Laipple, Daniel. Helmholtz-Zentrum Geesthacht; AlemaniaFil: Karmi, Fahim. Helmholtz-Zentrum Geesthacht; AlemaniaFil: Puszkiel, Julián Atilio. Helmholtz-Zentrum Geesthacht; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Jensen, Torben. University Aarhus; DinamarcaFil: Marini, Amedeo. Universita degli Studi di Pavia; ItaliaFil: Klassen, Thomas. Helmholtz-Zentrum Geesthacht; AlemaniaFil: Dornheim, Martin. Helmholtz-Zentrum Geesthacht; Alemani
2LiBH4–MgH2–0.13TiCl4 confined in nanoporous structure of carbon aerogel scaffold for reversible hydrogen storage
No full textThe investigations based on kinetic improvement and reaction mechanisms during melt infiltration, dehydrogenation, and rehydrogenation of nanoconfined 2LiBH4-MgH2-0.13TiCl4 in carbon aerogel scaffold (CAS) are proposed. It is found that TiCl4 and LiBH4 are successfully nanoconfined in CAS, while MgH2 proceeds partially. In the same temperature (25-500ºC) and time (0?5 h at constant temperature) ranges nanoconfined 2LiBH4-MgH2-0.13TiCl4 dehydrogenates completely 99% of theoretical H2 storage capacity, while that of nanoconfined 2LiBH4?MgH2 is only 94%. Nanoconfined 2LiBH4-MgH2-0.13TiCl4 performs three-step dehydrogenation at 140, 240, and 380ºC. Onset (the first-step) dehydrogenation temperature (140ºC), significantly lower than those of nanoconfined sample of 2LiBH4-MgH2 and 2LiBH4-MgH2-TiCl3 (DT = 140 and 110ºC, respectively) is in agreement with the decomposition of eutectic LiBH4-Mg(BH4)2 and lithium?titanium borohydride. For the second and third steps (240 and 380ºC),decompositions of LiBH4 destabilized by LiCl solvation and MgH2 are accomplished, respectively. In conclusion, dehydrogenation products are B, Mg, LiH, and TiH. Reversibility of nanoconfined 2LiBH4-MgH2-0.13TiCl4 sample is confirmed by the recovery of LiBH4 after rehydrogenation together with the formation of [B12H12] derivatives. The superior kinetics during the 2nd, 3rd, and 4th cycles of nanoconfined2LiBH4-MgH2-0.13TiCl4 to the nanoconfined 2LiBH4-MgH2 can be due to the formations of Ti-MgH2 alloys (Mg0.25Ti0.75H2 and Mg6TiH2) during the 1st rehydrogenation.Fil: Gosalawit Utke, Rapee. Institute of Materials Research; Alemania. Suranaree University of Technology; TailandiaFil: Milanese, Chiara. University of Pavia; ItaliaFil: Javadian, Payam. University of Aarhus; DinamarcaFil: Girella, Alessandro. University of Pavia; ItaliaFil: Laipple, Daniel. Institute of Materials Research; AlemaniaFil: Puszkiel, Julián Atilio. Institute of Materials Research; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cattaneo, Alice S.. University of Aarhus; DinamarcaFil: Ferrara, Chiara. University of Aarhus; DinamarcaFil: Wittayakhun, Jatuporn. Suranaree University of Technology; TailandiaFil: Skibsted, Jørgen. University of Aarhus; DinamarcaFil: Jensen, Torben R.. University of Aarhus; DinamarcaFil: Marini, Amedeo. University of Pavia; ItaliaFil: Klassen, Thomas. Institute of Materials Research; AlemaniaFil: Dornheim, Martin. Institute of Materials Research; Alemani
Improvement of thermal stability and reduction of LiBH4/polymer host interaction of nanoconfined LiBH4 for reversible hydrogen storage
No full textAddition of multi-wall carbon nanotube (MWCNT) and NaAlH4 into nanoconfined LiBH4
ePcB (poly (methyl methacrylate)ecoebutyl methacrylate) for improving thermal stability
and reducing LiBH4/PcB interaction is proposed. The greater the amount of gases desorbed
due to polymer (PcB) degradation, the less the thermal stability of polymer host. During
dehydrogenation of nanoconfined LiBH4ePcB, combination of gases due to PcB degradation
is 64.3% with respect to H2 content, while those of nanoconfined samples doped with
MWCNT and NaAlH4 are only 9 and 7.9%, respectively. The LiBH4/PcB (i.e., B/OCH3)
interaction is quantitatively evaluated by FTIR technique. The more the ratio of peak area
between y(BeH) (from LiBH4) and y(C]O) (from PcB), the lower the LiBH4/PcB interaction. It
is found that by adding small amount of MWCNT and NaAlH4, this ratio significantly increases
up to 78%. This is in agreement with B 1s XPS results, where the relative amount of
BxOy (x/y = 3) to LiBH4 decreases after adding MWCNT and NaAlH4 into nanoconfined LiBH4
ePcB. It should be remarked that significant improvement of thermal stability and decrease
of LiBH4/PcB interaction after adding MWCNT and NaAlH4 into nanoconfined LiBH4-PcB
result in considerable amount of hydrogen release and uptake as well as hydrogen
reproducibility during cycling. However, the dispersion of MWCNT is still one of the most
critical factors to be concerned due to probably its hindrance for hydrogen diffusion
Nanoconfined 2LiBH4-MgH2 for Reversible Hydrogen Storages: Reaction Mechanisms, Kinetics and Thermodynamics
No full textSamples of nanoconfined Reactive Hydride Composites in resorcinol–formaldehyde (RF) aerogel scaffolds are prepared by (i) direct melt infiltration of bulk 2LiBH4–MgH2; and (ii)
MgH2 impregnation and LiBH4 melt infiltration. The reaction mechanisms, kinetics and thermodynamics of the systems are determined. Activation energy (EA) and LiBH4 and MgH2
dehydrogenation enthalpies (Hdes, MgH2+ Hdes, LiBH4) of the nanoconfined 2LiBH4–MgH2 are in this work of interest. The hydrogen sorption reactions in both nanoconfined samples are reversible as shown by the recovering of LiBH4 and MgH2 after rehydrogenation. The titration results show the remarkable improvement in desorption kinetics of both nanoconfined samples over the bulk material, such as more than 90 % of overall hydrogen storage capacity is obtained
within 2 h for the nanoconfined samples during the 1st dehydrogenation, while that of bulk material needs more than 16 h. The activation energy of the composites decreases by 84–150 kJ/mol (EA) due to nanoconfinement. For thermodynamics, the dehydrogenation enthalpies of
LiBH4 and MgH2 (Hdes, MgH2+ Hdes, LiBH4) obtained from the nanoconfined sample reduces up to 10.61 kJ/mol H2 with respect to the bulk material
การพัฒนาวัสดุไฮไดรด์ของแมกนีเซียมเพื่อใช้ในการกักเก็บพลังงาน ไฮโดรเจนและแบตเตอรีชนิดของแข็ง
No full textโครงร่างเลี้ยงเซลล์เส้นใยนาโนอิเล็กโทรสปันจากไหมไฟโบรอินผสมพอลิไวนิลแอลกอฮอล์สำหรับการประยุกต์ใช้ในวิศวกรรมเนื้อเยื่อหมอนรองเข่า
No full textการกดอัด Li-N-H ในการเก็บไฮโดรเจน เพื่อการปรับปรุงคุณสมบัติทางจลนศาสตร์ และยับยั้งการปลดปล่อย NH3
No full textการเพิ่มประสิทธิภาพการดูดซับไฮโดรเจนของ LiBH4-LiAlH4 โดยหยุดการปลดปล่อยไฮโดรเจน การบด และการเติมมัลติวอลล์คาร์บอนนาโนทิวบ์
No full text
2LiBH(4)-MgH2 nanoconfined into carbon aerogel scaffold impregnated with ZrCl4 for reversible hydrogen storage
No full textNanoconfinement of 2LiBH(4)-MgH2 composite into carbon aerogel scaffold (CAS) impregnated with zirconium (IV) chloride (ZrCl4) for reversible hydrogen storage is proposed. Nanoconfined samples prepared with hydride:ZrCl4-doped CAS weight ratios of 1:1, 1:2, and 1:3 are prepared by melt infiltration technique. Successful nanoconfinement of all samples is confirmed and it is found that the sample with high content of hydride with respect to ZrCl4-doped CAS (1:1 weight ratio) shows partial pore blocking. The most suitable hydride:ZrCl4-doped CAS weight ratio providing the best performance based on dehydrogenation temperature and kinetics as well as hydrogen storage capacity is 1:2. Reduction of dehydrogenation temperature and faster kinetics are obtained after doping with ZrCl4. Up to 97 and 93% of theoretical hydrogen storage capacity are released and reproduced after four cycles of nanoconfined sample with ZrCl4 (1:2 weight ratio). Deficient hydrogen content with respect to theoretical capacity can be due to partial dehydrogenation during melt infiltration and formation of thermally stable [B12H12](2-) phases during cycling
