物理化学学报 >> 2025, Vol. 41 >> Issue (1): 100001.doi: 10.3866/PKU.WHXB202308032

所属专题: 能源化学

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杂多酸H3PW12O40高效催化MgH2储氢

于冉1, 胡晨1, 郭锐利2, 刘若男2, 夏力行1, 杨岑玉1, 水江澜2,3,*()   

  1. 1 中国电力科学研究院, 北京 100192
    2 北京航空航天大学材料科学与工程学院, 北京 100191
    3 天目山实验室, 杭州 310023
  • 收稿日期:2023-08-18 修回日期:2023-10-11 录用日期:2023-10-25 发布日期:2023-12-20
  • 通讯作者: Email: shuijianglan@buaa.edu.cn; Tel.: +86-13522516709 (水江澜)
  • 基金资助:
    国家电网公司(SGJSDK00KJJS2100323)

Catalytic Effect of H3PW12O40 on Hydrogen Storage of MgH2

Ran Yu1, Chen Hu1, Ruili Guo2, Ruonan Liu2, Lixing Xia1, Cenyu Yang1, Jianglan Shui2,3,*()   

  1. 1 China Electric Power Research Institute, Beijing 100192, China
    2 School of Materials Science and Engineering, Beihang University, Beijing 100191, China
    3 Tianmushan Laboratory, Hangzhou 310023, China
  • Received:2023-08-18 Revised:2023-10-11 Accepted:2023-10-25 Published:2023-12-20
  • Contact: Email: shuijianglan@buaa.edu.cn; Tel.: +86-13522516709 (Jianglan Shui)
  • Supported by:
    the State Grid Corporation of China(SGJSDK00KJJS2100323)

摘要:

本文研究了杂多酸对储氢材料的催化效应,通过机械球磨法制备MgH2-xH3PW12O40 (x = 7%、10%、13%,质量分数)复合物样品,与纯的球磨MgH2对比,展示了杂多酸H3PW12O40对MgH2储氢动力学的提升作用。其中,MgH2-10H3PW12O40的放氢活化能比纯MgH2降低了46.23 kJ∙mol−1,可在250 ℃、1 min内吸收6.25%的氢,在300 ℃、15 min内释放6.54%的氢气,而同等温度下MgH2在30 min内仅释放1.2%氢。即使是在较低的温度100 ℃,MgH2-10H3PW12O40也可在1 h内吸收5%的氢,而MgH2只能吸收0.9%的氢。结构表征结果表明H3PW12O40分子在球磨和储氢过程中被转变为WO3和W簇,其作用一方面是催化Mg―H键、H―H键的断裂,另一方面是促进MgH2颗粒在球磨过程中细化并抑制其团聚长大。该研究开创了多酸分子在储氢领域的催化应用。

关键词: 储氢材料, 氢化镁, 磷钨酸, 催化, 动力学性能

Abstract:

Developing hydrogen energy to replace carbon-rich fossil fuels is the future direction of energy technology, but there is still a lack of safe and efficient hydrogen storage technology. Hydrogen storage in solid medium is a relatively safe way to store hydrogen, among which magnesium hydride (MgH2) is one of the most promising solid hydrogen storage materials. MgH2 has the advantages of high hydrogen storage density, low cost and good reversibility of hydrogen absorption and release. However, improving its poor thermodynamic and slow kinetic characteristics are still challenging. Catalysts derived from polyoxometalates have been successfully used for catalyzing hydrogen evolution reaction, oxidation of organic compounds, desulfurization reaction, and so on. However, these catalysts have not been applied to the hydrogen storage materials yet. In this paper, H3PW12O40 is selected as a representative of polyoxometalates and its catalytic effect on hydrogen storage is studied. MgH2-xH3PW12O40 (x = 7%, 10%, 13%, mass percentage) and pure MgH2 samples are prepared by mechanical ball milling method. Among them, MgH2-10H3PW12O40 exhibits the optimal performance in both kinetic characteristic and hydrogen storage capacity. It can rapidly absorb 6.25% hydrogen within 1 min at 250 ℃ and release 6.54% hydrogen within 15 min at 300 ℃, while ball-milled MgH2 only releases 1.2% hydrogen within 30 min at 300 ℃. At the same time, the activation energy of the composite decreases to 106.08 kJ∙mol−1, which is 46.23 kJ∙mol−1 lower than MgH2. The catalytic effect of H3PW12O40 on the hydrogen storage properties of MgH2 mainly comes from three aspects. Firstly, the addition of H3PW12O40 helps to avoid the agglomeration of MgH2 during the ball milling process, which makes the MgH2 particles become smaller after ball milling, thus increasing the specific surface area of the interaction with hydrogen. Secondly, the addition of H3PW12O40 makes MgH2 produce a large number of defects and lattice distortion during ball milling, which provides more channels for hydrogen diffusion. Thirdly, the catalytic components of WO3 and W are in situ formed during the ball milling process. They can be used as active components to accelerate the electron migration process, which promotes the cleavage of the Mg―H bond and the adsorption and dissociation of hydrogen.

Key words: Hydrogen storage material, MgH2, Phosphotungstic acid, Catalysis, Kinetics property