Qiu Junqi, Yang Ying, Wan Haiyi, Sun Shixin, Chen Yu'an, Pan Fusheng
College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China.
Chongqing Institute of New Energy Storage Materials and Equipment, Chongqing 401135, China.
J Phys Chem Lett. 2025 Aug 14;16(32):8084-8091. doi: 10.1021/acs.jpclett.5c01248. Epub 2025 Jul 31.
Improving the low temperature hydrogen storage kinetics of Mg-based alloys is challenging due to the antagonistic effects of elements on hydrogen dissociation and diffusion during hydrogen absorption/desorption critically determining the hydrogen storage properties of materials, but the synergistic catalytic effect of different elements offers a promising way to address these issues. This study fabricated TiV alloy through high-energy ball milling and subsequently integrated them with Mg-Ni to establish a multiphase composite system for enhanced hydrogen storage applications. Through systematic characterization, we elucidated the synergistic interactions between hydrogenophilic (Ti/V) and hydrogen-repellent elements (Ni) in regulating hydrogenation thermodynamics and kinetics. The TiV-modified Mg-20Ni composite exhibited accelerated dehydrogenation kinetics, achieving 3.0 wt % hydrogen desorption within 40 min at 225 °C. Differential scanning calorimetry (DSC) analysis revealed a reduced desorption activation energy of 82.0 kJ/mol for the TiV-containing composite, representing a sharp decrease compared with the baseline Mg-20Ni system. The enhanced sorption kinetics might originate from TiV-catalyzed Mg-H bond destabilization and asymmetric hydride phase transformations during hydrogen cycling.
由于元素在吸氢/脱氢过程中对氢解离和扩散的拮抗作用严重决定了材料的储氢性能，因此改善镁基合金的低温储氢动力学具有挑战性，但不同元素的协同催化作用为解决这些问题提供了一条有前景的途径。本研究通过高能球磨制备了TiV合金，随后将其与Mg-Ni结合，建立了一种用于增强储氢应用的多相复合体系。通过系统表征，我们阐明了亲氢元素（Ti/V）和憎氢元素（Ni）在调节氢化热力学和动力学方面的协同相互作用。TiV改性的Mg-20Ni复合材料表现出加速的脱氢动力学，在225℃下40分钟内实现了3.0 wt%的氢解吸。差示扫描量热法（DSC）分析表明，含TiV的复合材料的解吸活化能降低至82.0 kJ/mol，与基线Mg-20Ni体系相比大幅下降。吸附动力学的增强可能源于TiV催化的Mg-H键不稳定以及氢循环过程中的不对称氢化物相变。
