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无机材料学报

• 研究论文 •    

溶胶-凝胶法制备TiO2增强LiAlH4放氢性能

郑雪萍1, 胡春旭1, 李雪1, 马秋花2, 梁琳坤1, 刘文帅1, 刘胜林1   

  1. 1.长安大学 材料科学与工程学院, 西安 710061;
    2.河南工业大学 材料科学与工程学院, 郑州 450000
  • 收稿日期:2025-12-12 修回日期:2026-03-01
  • 作者简介:郑雪萍(1977-), 女, 副教授. E-mail: zhengxueping2004@163.com
  • 基金资助:
    西安市2025年度“科学家+工程师”队伍建设项目(2025JH-KXGC-0015)

Enhancing the Hydrogen Release Performance of LiAlH4 by TiO2 Prepared via the Sol-Gel Method

ZHENG Xueping1, HU Chunxu1, LI Xue1, MA Qiuhua2, LIANG Linkun1, LIU Wenshuai1, LIU Shenglin1   

  1. 1. School of Materials Science and Engineering, Chang'an University, Xi'an 710061, China;
    2. School of Materials Science and Engineering, Henan University of Technology, Zhengzhou 450000, China
  • Received:2025-12-12 Revised:2026-03-01
  • About author:ZHENG Xueping (1977-), male, associate professor. E-mail: zhengxueping2004@163.com
  • Supported by:
    Xi'an Science and Technology Bureau 2025 Scientist + Engineer Team Construction Project (2025JH-KXGC-0015)

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摘要： 氢化铝锂(LiAlH4)因其高的理论储氢容量(质量分数约10.5%)被视为极具潜力的固态储氢材料, 但其较高的热分解温度与缓慢的动力学严重制约了实际应用。过渡金属氧化物TiO2作为有效的催化剂, 在改善储氢材料性能方面展现出潜力, 然而商业TiO2形貌与结构不可控, 难以进一步提升其催化性能。本研究采用溶胶-凝胶法制备具有大比表面积和丰富缺陷的纳米TiO2催化剂, 将不同质量分数(1%、3%、5%、7%)的自制TiO2与LiAlH4通过球磨复合, 系统研究了其放氢性能。结果表明, 5%(质量分数)TiO2的掺杂效果最优, 使LiAlH4的起始放氢温度降至112 ℃, 较纯LiAlH4(165 ℃)降低了53 ℃。在200 ℃恒温条件下, 该复合体系可在更短时间内完成放氢, 总放氢量达7.84%(质量分数), 且放氢总时间较纯LiAlH4缩短约30 min。即使在150 ℃较低温度下, 掺杂样品仍能释放4.64%(质量分数)的氢气, 远超纯LiAlH4在此温度下的放氢量(质量分数<1%)。动力学分析表明, TiO2掺杂使LiAlH4第一步放氢反应的活化能从116 kJ/mol显著降低至55.6 kJ/mol, 降幅高达52%。LiAlH4放氢性能显著提升源于放氢过程中原位生成的AlTi和LiAl活性中间相, 它们作为高效的催化活性中心, 为氢气分子的重组与脱附提供了新路径。本研究不仅证实了通过溶胶-凝胶法合成TiO2可有效突破商业催化剂性能瓶颈, 还为设计下一代高性能储氢材料催化剂提供了新的思路与实验依据。

关键词: LiAlH4, TiO2, 掺杂, 放氢性能, 反应活化能

Abstract: Lithium alanate (LiAlH4) is considered a promising solid-state hydrogen storage material due to its high theoretical hydrogen capacity (mass fraction about 10.5%). However, its practical application is hampered by high decomposition temperatures and sluggish kinetics. Titanium dioxide (TiO2) has shown potential as an effective catalyst for improving the dehydrogenation properties of hydrides. Nevertheless, the catalytic performance of commercial TiO2 is often limited by its uncontrollable morphology and structure. To overcome this limitation, this study used the Sol-Gel method to synthesize nanostructured TiO2 catalysts with high specific surface area and abundant defects. The as-prepared TiO2 was ball-milled with LiAlH4 at different mass ratios (1%, 3%, 5%, and 7%) to form composites, whose dehydrogenation properties were systematically investigated. Results demonstrated that the 5% (in mass) TiO2-doped sample exhibited optimal performance, lowering the onset dehydrogenation temperature of LiAlH4 to 112 ℃, which is 53 ℃ lower than that of pristine LiAlH4 (165 ℃). Under isothermal conditions at 200 ℃, the composite released a total hydrogen capacity of 7.84% (in mass) within a significantly shorter time, completing dehydrogenation approximately 30 min faster than the undoped sample. Even at a lower temperature of 150 ℃, the doped sample released 4.64% (in mass) hydrogen, far exceeding the capacity of pure LiAlH4 (<1% (in mass)) at the same temperature. Kinetic analysis revealed that TiO2 doping reduced the activation energy for the first dehydrogenation step from 116 kJ/mol to 55.6 kJ/mol, a remarkable decrease of 52%. In-situ formation of active AlTi and LiAl intermediate phases during dehydrogenation played a critical role, which served as efficient catalytic centers, providing new pathways for hydrogen recombination and desorption. This work not only verifies that TiO2 synthesized via the Sol-Gel method can effectively break through the performance ceiling of commercial catalysts, but also offers new insights and experimental basis for designing next-generation high-performance catalysts for hydrogen storage materials.

Key words: LiAlH4, TiO2, doping, hydrogen release property, reaction activation energy

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