《Advanced Energy Materials》MgH₂储氢再提速：五元高熵氧化物催化实现195℃低温脱氢与室温秒级吸氢

2026-05-22 11:25:59, CIQTEK 国仪量子技术（合肥）股份有限公司

氢能规模化应用的核心瓶颈在于安全、高效、低成本的储运技术。作为典型固态储氢材料，MgH₂具有高理论储氢容量、优异体积储氢密度、资源丰富和环境友好等优势，被认为是极具产业化潜力的金属氢化物体系。然而，受强Mg-H键和较高反应焓限制，MgH₂长期面临脱氢温度高、吸脱氢动力学慢、低温响应不足等难题。传统单一金属或单一氧化物催化剂虽可改善反应速率，但通常难以同时兼顾低温脱氢、快速吸氢和循环稳定性。因此，构建稳定且具备多活性位点协同作用的催化界面，成为提升MgH₂储氢性能的关键突破口。

针对这一问题，西安工业大学某团队提出了五元Ti基金红石型高熵氧化物催化调控策略，通过溶胶凝胶法构筑(TiNbCrTaFe)O₂高熵氧化物，并将其引入MgH₂储氢体系。实验结果表明，该催化剂可显著降低MgH₂脱氢温度，提升低温吸/脱氢动力学，并表现出良好的循环稳定性。这一工作将高熵氧化物的结构复杂性与MgH₂催化改性需求相结合，为金属氢化物储氢材料的高效催化设计提供了新的思路。

高熵氧化物催化剂设计

从“单一活性位”到“多工位协同催化”

MgH₂的吸/脱氢过程并非单一步骤反应，而是涉及H₂吸附解离、H原子迁移、Mg-H键断裂/生成以及Mg/MgH₂相变等多个连续环节。传统单一组分催化剂通常只能针对其中部分步骤发挥作用，而(TiNbCrTaFe)O₂高熵氧化物的优势在于其多元素随机占位所带来的结构和电子双重调控：一方面，晶格畸变和氧空位为氢迁移与界面反应提供了更多活性通道；另一方面，多价态过渡金属中心有利于促进电子转移和Mg-H键活化，从而实现对MgH₂吸/脱氢全过程的协同催化。

低温脱氢动力学性能分析

程序升温脱氢结果显示，纯MgH₂起始脱氢温度约为358°C；MgH₂ + 10 wt.%TiO₂降至237°C；MgH₂ + 10 wt.% HEO进一步降至195°C，较纯MgH₂降低163°C

在220、235、250和265°C下，MgH₂ + 10 wt.% HEO分别可在19、16、10和9 min内基本完成脱氢，对应脱氢量为4.49、4.80、5.88 和5.98 wt.% H₂

在250°C下，该体系10 min释放5.88 wt.% H₂，平均脱氢速率达到0.588 wt.% min^-1，优于文中对比的大多数高熵催化剂改性MgH₂体系

JMAK与Arrhenius拟合表明，复合体系表观脱氢活化能降至54.62 ± 1.93 kJ mo^-1，相比纯MgH₂的130.51 ± 19.95 kJ mol^-1显著降低

室温快速吸氢与低压吸氢性能分析

在50 bar H₂条件下，该复合材料在200、150、100和50°C下均能在20 s内完成快速初始吸氢，对应吸氢量分别为5.74、5.04、3.51和2.74 wt.% H₂

即使在室温25°C下，材料也能在20 s内吸收1.84 wt.% H₂，说明高熵氧化物显著改善了H₂捕获、活化和初始氢化过程

在50°C、30 bar和10 bar H₂条件下，复合体系1 h吸氢量分别达到2.86和2.48 wt.%，显示出一定低压适应性

Figure 3. Hydrogen storage performance. (a) Temperature-programmed desorption curves of MgH₂+10 wt.% HEO compared with pristineMgH₂ and MgH₂+10 wt.% TiO₂. (b) Isothermal hydrogen desorption profiles of MgH₂+10 wt.% HEO at various temperatures. (c) Isothermal hydrogenabsorption curves of MgH₂+10 wt.% HEO at various temperatures under 50 bar H₂. (d) Isothermal hydrogen absorption profiles of MgH₂+10 wt.% HEO at 50℃ under different H₂ pressures. (e) JMAK plots of MgH₂+10 wt.% HEO at various temperatures. (f) Arrhenius plots of MgH2+10 wt.% HEO. (g) Comparison of the isothermal dehydrogenation performance of MgH₂+10 wt.% HEO with that of previously reported MgH₂-based high entropy catalyst systems at corresponding temperatures. (h) Isothermal de/hydrogenation cycling curves of MgH₂+10 wt.% HEO at 300℃. (i) Isothermal dehydrogenation curves of MgH₂+10 wt.% HEO for the first, second, 3th, fifth and 10th cycles.

结构稳定性与相演化

高熵氧化物能否扛住MgH₂还原环境？

MgH₂反应环境具有较强还原性，许多氧化物催化剂在循环过程中可能发生相变、元素偏析或与Mg生成二次相，导致催化活性衰减。本文通过XRD、XPS、EPR、TEM和EDS mapping追踪循环过程中的相演化。

循环稳定性与相结构分析

XRD结果显示，吸/脱氢过程中MgH₂与Mg之间可逆转化，同时出现少量MgO，但未观察到明显新的金属间化合物或催化剂分解相

XPS与EPR表明，初始循环后氧空位浓度增加并逐渐稳定，这可能是第二圈脱氢动力学优于第一圈的重要原因

10次吸/脱氢循环后，体系仍保持6.44 wt.%的储氢容量，相比初始6.52 wt.%容量保持率为98.8%

TEM/EDS结果显示Ti、Nb、Cr、Ta、Fe在Mg/MgH₂基体中仍保持较均匀分布，未出现明显相分离或元素偏析

Figure 4. Phase evolution. Structural and compositional characterization of MgH₂+10 wt.% HEO at different stages, including the ball-milledstate and the first and 10th de/hydrogenation cycles: (a) XRD patterns; (b) O 1s XPS spectra; (c) EPR spectra. TEM, SAED, HRTEM, and elemental EDS mapping images of MgH₂+10 wt.% HEO during; (d-f) the first dehydrogenation and; (g-i) the 10th dehydrogenation cycles.

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近期助力成果目录

1.Solvent-mediated partial ionicity enhances mechanical nanosizing effect of Mg-based hydrogen storage alloys. Nature Communications (2026)

2.Room-Temperature Alane Dehydrogenation for Visible-Light-Driven Photocatalytic Hydrogen Supply System. Advanced Science (2025)

3.Dual‐Stage Heat Treatment for Enhanced Hydrogen Storage Properties of Mg-N-Y Alloys. Rare Metals (2026)

4. A novel carbon-induced-porosity mechanism for improved cycling stability of magnesium hydride. Journal of Magnesium and Alloys (2025)

5.Impacts of Y addition on the hydrogen storage performance of Ti-Zr-Mn-Cr-Fe alloys. Journal of Alloys and Compounds (2026)

6. Effect of Ni doping on hydrogen storage kinetics and thermodynamic properties of ball-milled Nd-Mg alloy. Journal of Alloys and Compounds (2025)

7. Superior de/hydriding kinetics and cycling stability of Mg-CeAl₃@CeH₂ nanocomposites. Journal of Alloys and Compounds (2025)

8.Doping-induced enhanced hydrogenation resistance and structural stability in SmCo₅ permanent magnets: A combined theoretical and experimental study. Journal of Alloys and Compounds (2026)

9. Breaking kinetic and thermodynamic barriers: CeO₂-Ni-rGO synergistic catalysis for comprehensively enhanced hydrogen storage performance of MgH₂. Journal of Alloys and Compounds (2026)

10.Structural and Phase Evolution in the Mg-Al System Leading to Lower Hydrogen Desorption Temperature. Hydrogen (2025)

11.Interpretable machine learning framework for hydrogen storage capacity prediction in Ti-Zr-Mn-Cr-V high-entropy alloys: Influenced by valence electron average. Journal of Energy Storage (2026)

12.Dual-strategy regulation for enhancing hydrogen storage performance of non-activated Mg₈Ni-TiO₂/MnO₂ composites. Journal of Energy Chemistry (2025)

13.Nanoscale effect of spontaneous combustion of sulfur corrosion products: Oxygen adsorption and activation mechanism dominated by mesopores. Fuel (2026)

14.Pore structure reconfiguration and microscale fluid response in bituminous coal under CO₂ and flue gas-enhanced coalbed methane recovery. Fuel (2026)

15. Experimental and theoretical investigation on hydrogen storage performance of titanium decorated hexagonal boron nitride. Applied Surface Science (2026)

16.Cu-based methanol steam reforming catalyst supported by heat conduction enhanced GO+UiO-66 composite MOF material for long-term stable hydrogen production. International Journal of Hydrogen Energy (2025)