JOURNAL OF ALLOYS AND COMPOUNDS
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2025
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IF 6.3
Cheng Lv,Jiayan Huang,Yuang QI,Qingjie He,Yazhou Wang,Cuili Xiang,Yongjin Zou,Fen Xu,Lixian Sun
MgH₂ is one of the most promising materials for solid hydrogen storage and is environmentally friendly primarily owing to its high mass hydrogen storage density (7.6 %). However, the application and development of MgH₂ are limited by its sluggish kinetics, requiring high processing temperatures. In this study, we prepared Ni/Co-co-doped Ti 2 VC 2 bimetallic MXene nanosheets via etching and the hydrothermal method. These nanosheets were then doped into MgH₂, resulting in drastically improved hydrogen storage properties. The MgH₂-based composite hydrogen storage materials doped with 10 wt% Ni/Co–Ti 2 VC₂ (TVCNC) commenced hydrogen emission from 183 °C and could emit 6.65 wt% hydrogen at 300 °C. During the rehydrogenation test, the composites could still absorb hydrogen at 5.0 wt% within a 10 min window at a hydrogen pressure of 20 bar at 125 °C. Moreover, the hydrogen absorption and emission kinetics of the doped MgH₂ were considerably improved. This improvement could be ascribed to the significantly increased specific surface area of the MXene nanosheets after etching, which increased the number of active sites on the surface to accelerate the reaction, thereby accelerating hydrogen adsorption and emission. In addition, the migration of electrons between the multivalent Ti ions as well as between Ni and Co helped accelerate bond cleavage between magnesium and hydrogen, thereby enhancing the kinetic properties. Ni/Co co-doping produced Mg 2 Ni alloys with magnesium via hydrogen adsorption and emission, thus improving the reaction kinetics of the composites.
研究领域:
材料科学
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能源储存
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2025
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IF 13.2
Wenqing Chen,Jia Liu,Tianshuo Liu,Xiaowei Chen
Solid-state hydrogen storage via MgH 2 offers high volumetric density, safety, and energy efficiency but is hampered by high H 2 desorption temperatures and sluggish kinetics. Although nanostructured catalysts enhance performance, their complex synthesis and instability limit viability. We present a one-step strategy that leverages metal acetylacetonates (M(acac) n ) to address these challenges. Combined V(acac) 3 with MgH 2 enables the in situ formation of a highly dispersed V-O-Mg interfacial layer, markedly enhancing H 2 sorption kinetics, achieving an onset dehydrogenation temperature of 170 °C, low temperature H 2 desorption (5.3 wt% at 184 °C) and absorption (4.3 wt% at 24 °C), and excellent cycling stability (95.6 % retention after 100 cycles). Kinetic analysis reveals that dehydrogenation initiates via two-dimensional nucleation-growth and transitions to a temperature-dependent mechanism at high conversion (α > 0.3). Density functional theory indicates that V-induced surface reconstruction and charge redistribution lower the H 2 desorption barrier. Additionally, Zr(acac)₄ and TiO(acac)₂ show similar performance improvements, suggesting a promising pathway for optimizing MgH 2 using metal acetylacetonate-based catalysts.
研究领域:
材料科学
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能源化学
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物理化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2024
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IF 5.8
Zhenji Li,Zhao Zhang,Jun Guo,Hongwei Jia,Wei Zhao,Lijun Lei,Que Huang,Lang Han,Changcheng Liu,Li Guo
MgH₂ is recognized as a promising material for hydrogen production due to its high hydrogen density, abundant availability, and non-polluting hydrolysis by-products, making it a viable hydrogen source for fuel cells. This study, for the first time, investigates the hydrogen production performance of the MgH₂-MOx-NaH (M = Ti, Zr, Mo, Fe, V, Bi) system, which exhibits remarkable hydrolysis properties in aqueous solutions. A series of MgH₂-MOx-NaH composite powders were synthesized via mechanical ball milling. The results revealed that V₂O₅-NaH and Bi₂O₃-NaH significantly enhanced the hydrolysis performance of MgH₂ for hydrogen production. Specifically, Bi₂O₃-NaH and V₂O₅-NaH effectively refined MgH₂ particles and mitigated agglomeration during the milling process. Hydrolysis tests demonstrated that the conversion rate and the hydrogen generation rate (mHGR) of composites initially increased with ball milling time and then decreased. The maximum hydrolysis hydrogen production yield and conversion rate for MgH₂-Bi₂O₃-NaH and MgH₂-V₂O₅-NaH composites occurred at a ball milling duration of 10 hours, and reached up to 1354.1 mL g⁻¹ (88.5 %) and 1273.5 mL g⁻¹ (81.8 %), respectively, within 8 minutes. Kinetic tests of hydrolysis hydrogen production showed that the reaction rate and hydrogen conversion increased with elevated hydrolysis temperatures. The activation energies for the hydrolysis of MgH₂-MOx-NaH (M = Ti, Zr, Mo, Fe, V, Bi) were calculated from the hydrolysis-hydrogen production curves using the Arrhenius formula, yielding values of 41.32, 37.66, 36.40, 34.60, 30.80, and 27.17 kJ mol⁻¹, respectively. The lower activation energies for hydrolysis indicate improved reaction kinetics, suggesting that the incorporation of transition metal oxides and sodium hydride effectively enhances both the hydrolytic conversion and reaction rate of MgH₂.
研究领域:
材料科学
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能源工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）