arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2501.04516cond-mat.mtrl-sci
收藏

Al-Cu-Fe-Ni-Cr高熵合金的催化活性

Catalytic activity of Al-Cu-Fe-Ni-Cr high entropy alloy

Yogesh Kumar Yadav, Mohammad Abu Shaz, Thakur Prasad Yadav

AI总结:

本文研究机械合金化制备的Al-Cu-Fe-Ni-Cr高熵合金对MgH2储氢的催化作用,显著降低放氢温度、提升吸放氢动力学与循环稳定性,并提出催化机制。

摘要:

氢化镁(MgH2)因其资源丰富以及在温和条件下具有高储氢容量和成本效益等优良性能,是一种很有前景的储氢材料。尽管具备这些优势,MgH2不利的热力学和动力学性能使其难以在实际应用中使用。本研究采用通过机械合金化合成的Al-Cu-Fe-Ni-Cr高熵合金(HEA)基催化剂,改善了MgH2的储氢性能。实验结果表明,在MgH2中添加5 wt.%的Al-Cu-Fe-Ni-Cr HEA后,MgH2的起始放氢温度从425°C显著降至180°C。此外,该催化剂表现出增强的动力学性能:在320°C、15 atm氢压下,3分钟内吸收7.3 wt.%的氢;在320°C下,6分钟内放氢约5 wt.%。这些结果突显其放氢温度相比其他知名催化剂低多少。在25次循环过程中,经Al-Cu-Fe-Ni-Cr HEA催化的MgH2表现出显著的循环稳定性,波动可忽略不计(约0.05 wt.%)。在对材料进行全面表征后,依据结果提出了HEA可行的催化机制。

英文摘要:

Magnesium hydride (MgH2) is a promising material for hydrogen storage because of its abundance and beneficial properties, such as high storage capacity and cost-effectiveness under mild conditions. Despite of these benefits, MgH2 unfavorable thermodynamics and kinetics make it difficult to use in real applications. In this work, the hydrogen storage properties of MgH2have been improved using Al-Cu-Fe-Ni-Cr high entropy alloy (HEA) based catalysts, which has been synthesized via mechanical alloying. The experimental findings show that the beginning desorption temperature of MgH2significantly lowered from 425°C to 180°C by adding 5 wt. % Al-Cu-Fe-Ni-Cr HEA in MgH2. Moreover, the catalyst shows enhanced kinetics, attaining 7.3 wt. % hydrogen absorption in 3 minutes at 320°C with 15 atm hydrogen pressure, and ~5 wt. % desorption in 6 minutes at 320°C. These results highlight, how much lower its desorption temperature is than those of other well-known catalysts. Over a span of 25 cycles, MgH2 catalyzed by Al-Cu-Fe-Ni-Cr HEA exhibits remarkable cyclic stability with negligible fluctuations (~ 0.05 wt. %).After a thorough characterization of the materials, a workable catalytic mechanism for HEA was proposed in light of the results.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑