Stability, reactivity and decomposition kinetics of surface passivated α-AlH3 crystals

Yu, Minghui; Xie, Wuxi; Zhu, Zhaoyang; Yan, Qi‐Long

doi:10.1016/j.ijhydene.2021.12.212

Cited by 17 publications

(13 citation statements)

References 43 publications

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“…As seen in Figure a, the original AlH 3 particle is assumed to be a spherical shape with an amorphous Al 2 O 3 layer on surface. Studies have shown that the primary passivated layer of Al 2 O 3 is unstable and tends to undergo hydration reactions with water, which results in the formation of multihole layers of AlOOH or Al(OH) 3 . , Once water or oxygen passes through the defects, it could react with the metallic Al core to generate H 2 bubbles, which eventually destroy the Al 2 O 3 layer. After modification by PFPE, the coating is adsorbed on the surface of AlH 3 .…”

Section: Resultsmentioning

confidence: 99%

“…17 Surface passivation or functionalization has great potential to enhance the stability of AlH 3 among the mentioned methods. In our recent research, 18 the stability of AlH 3 was improved by surface passivation in acidic media, which resulted in an improvement of both the initial decomposition temperature and the dehydrogenation activation energy by 5.6 °C and 22.3 kJ• mol −1 , respectively. In general, there is a layer of amorphous Al 2 O 3 on the surface of AlH 3 , which could limit the spontaneous decomposition and ensure the safety of AlH 3 in practical engineering applications.…”

Section: ■ Introductionmentioning

confidence: 95%

“…Surface passivation or functionalization has great potential to enhance the stability of AlH 3 among the mentioned methods. In our recent research, the stability of AlH 3 was improved by surface passivation in acidic media, which resulted in an improvement of both the initial decomposition temperature and the dehydrogenation activation energy by 5.6 °C and 22.3 kJ·mol –1 , respectively.…”

Section: Introductionmentioning

confidence: 99%

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Stabilization of AlH₃ Crystals by the Coating of Hydrophobic PFPE and Resulted Reactivity with Ammonium Perchlorate

Yang

Xie³

et al. 2023

Langmuir

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Aluminum hydride (AlH 3 ) is a promising fuel component of solid propellant, but its stabilization is still challenging. Herein, surface functionalization of hydrophobic perfluoropolyether (PFPE) followed by ammonium perchlorate (AP) coating has been implemented. In particular, AlH 3 @PFPE@xAP (x = 10, 30, 50, or 64.21%) composites (AHFPs) were prepared by a spraydrying technique. The PFPE-functionalized AlH 3 with a hydrophobic surface shows an increased water contact angle (WCA) from 51.87°to 113.54°. Compared with pure AlH 3 , the initial decomposition temperatures of AHFPs were increased by 17 °C, and the decomposition properties of AP in the AHFPs were also enhanced with significantly decreased peak temperature and fairly increased energy output. Moreover, the decomposition induction time of AHFPs-30% was improved by almost 1.82 times that of raw AlH 3 , which indicates that the coatings of PFPE and AP could improve the stability of AlH 3 . The maximum flame radiation intensity of AHFPs-30% was 21.6 × 10 3 , which is almost 7.71 times that of pure AlH 3 (2.8 × 10 3 ).

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Section: Resultsmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Stabilization of AlH₃ Crystals by the Coating of Hydrophobic PFPE and Resulted Reactivity with Ammonium Perchlorate

Yang

Xie³

et al. 2023

Langmuir

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“…Sankrack and Reilly have found that the formation of α‐AlH 3 can enhance the hydrogen molecular desorption kinetics 23 . The structural and decomposed dynamics of α‐AlH 3 are studied by the Yu and Xie at al 24 . In addition, Maehlen has applied the in situ method to synthesize the γ‐AlH 3 25 .…”

Section: Introductionmentioning

confidence: 99%

“…23 The structural and decomposed dynamics of α-AlH 3 are studied by the Yu and Xie at al. 24 In addition, Maehlen has applied the in situ method to synthesize the γ-AlH 3 . 25 When γ-AlH 3 is decomposed, 60% hydrogen gas is released and 40% γ-AlH 3 is transformed to α-AlH 3 .…”

Section: Introductionmentioning

confidence: 99%

New insight into the structural and physical properties of AlH ₃

Pan

2022

Intl J of Energy Research

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Summary AlH3 hydride is a typical hydrogen storage material due to the high storage, low density and low temperature decomposition temperature, but the structural feature of AlH3 remains controversial. In addition, the optical properties of AlH3 are unclear. In this work, the first‐principles method is used to study the structural, optical and electronic properties of AlH3 hydride. Two possible AlH3 hydrides, viz. rhombohedral and cubic structures are considered. The stability of the rhombohedral AlH3 is demonstrated based on the analysis of phonon dispersion. Moreover, the band gap of rhombohedral and cubic AlH3 is 2.170 and 0.656 eV, respectively. Naturally, the semiconductor feature of AlH3 is related to the band separation of H‐s state and Al‐3p state. The dielectric functional diagram demonstrates the semiconductor properties of AlH3 hydride. Furthermore, it is found that the AlH3 shows the ultraviolet response.

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Reduction of agglomeration effect by aluminum trihydride in solid propellant combustion

Gou,

Hu,

et al. 2023

Propellants Explo Pyrotec

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Aluminum trihydride (AlH3) has gained considerable attention as a substitute fuel for aluminum in solid propellants. In this study, we conducted a systematic investigation to evaluate the effects of AlH3 content, ranging from 0 % to 18 %, on propellant ignition, combustion, and agglomeration. Experimental methods such as thermogravimetry−differential scanning calorimetry (TG‐DSC), laser ignition, high‐speed photography, and collecting condensed combustion products (CCPs) were employed. The results indicate that AlH3 significantly promotes the high‐temperature decomposition of ammonium perchlorate (AP). Meanwhile, the addition of cyclotetramethylene tetranitramine (HMX) in propellant does not affect the hydrogen release reaction of AlH3. As the AlH3 content increases from 0 % to 18 %, the spectral emission intensity of the propellants decreases, and the ignition delay time initially increases from 253 ms to 321 ms, and then decreases to 258 ms. Furthermore, the burning rate increases with increasing the AlH3 content, while the pressure exponent is reduced from 0.551 to 0.460. The inclusion of AlH3 in propellants significantly inhibits aluminum agglomeration near the burning surface. Additionally, as the AlH3 content increases, the mean particle size D43 of the CCPs decreases from 50.95 μm to 8.28 μm at 1 MPa. The agglomeration degree of aluminum is very weak at 7 MPa, especially when the AlH3 content exceeds 9 %. The conclusions drawn from this study can serve as valuable guidance for optimizing propellant formulations.

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Stability, reactivity and decomposition kinetics of surface passivated α-AlH3 crystals

Cited by 17 publications

References 43 publications

Stabilization of AlH₃ Crystals by the Coating of Hydrophobic PFPE and Resulted Reactivity with Ammonium Perchlorate

Stabilization of AlH₃ Crystals by the Coating of Hydrophobic PFPE and Resulted Reactivity with Ammonium Perchlorate

New insight into the structural and physical properties of AlH ₃

Reduction of agglomeration effect by aluminum trihydride in solid propellant combustion

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Stability, reactivity and decomposition kinetics of surface passivated α-AlH3 crystals

Cited by 17 publications

References 43 publications

Stabilization of AlH3 Crystals by the Coating of Hydrophobic PFPE and Resulted Reactivity with Ammonium Perchlorate

Stabilization of AlH3 Crystals by the Coating of Hydrophobic PFPE and Resulted Reactivity with Ammonium Perchlorate

New insight into the structural and physical properties of AlH 3

Reduction of agglomeration effect by aluminum trihydride in solid propellant combustion

Contact Info

Product

Resources

About

Stabilization of AlH₃ Crystals by the Coating of Hydrophobic PFPE and Resulted Reactivity with Ammonium Perchlorate

Stabilization of AlH₃ Crystals by the Coating of Hydrophobic PFPE and Resulted Reactivity with Ammonium Perchlorate

New insight into the structural and physical properties of AlH ₃