Al3V/AlV3间原位转变对连续壳层镁纳米储氢颗粒的界面演变作用机制

镁基储氢材料容量大、价格低等优点使其在车载储氢等诸多领域具有广阔应用前景。铝与金属钒能形成金属间化合物，但其作为催化剂对连续壳层Mg作用效果尚需深入的研究。此外，作为纳米限域的一种方式，构建含催化剂连续壳层Mg-Al系复合纳米颗粒以发挥纳米化和催化作用仍存在巨大挑战。本项目拟通过氢等离子金属反应及球磨法制备Al3V及AlV3/连续壳层镁复合纳米颗粒，厘清储氢过程中界面转变与储氢性能的关联。通过研究Al3V和AlV3的储氢特性，重点揭示吸放氢过程Al3V/AlV3间原位转变时Mg纳米颗粒壳层连续性变化及界面演变规律，进而建立模型计算不同温度界面自由能，最后采用第一性原理计算界面氢吸附、解离、扩散和空位形成能，从动力学及热力学方面阐明Al3V/AlV3间原位转变时催化剂微观作用机理。本项目的实施将显著改善镁基储氢材料的动力学性能及操作温度，为构建含催化剂的连续壳层镁储氢材料提供理论及实验基础。

Magnesium based hydrogen storage material is very promising in field of on-board hydrogen storage systems for its high storage capacity and low price characteristics. Al and V can form intermetallic compounds, but the effects of those compounds used as catalyst on the continuous shell of Mg still need further studies. Furthermore, as a method of nano-confinement, constructing continuous shell coated Mg-Al nanocomposites containing catalyst to combine nanosizing and catalytic effects are still great challenges. This project intends to prepare Al3V/AlV3 intermetallic compound/continuous shell coated Mg nanocomposite by hydrogen plasma metal reaction and ball milling method. Clarifying correlation between interfacial transformation of the Al3V/AlV3 and hydrogen storage performance of the nanocomposite. The hydrogen storage feature of the Al3V and AlV3 would be studied. Moreover, the effect clarification of in-situ transformation of Al3V/AlV3 on the continuity and interface evolution of continuous shell-coated Mg nanocomposite during hydrogen absorption and desorption process would be an important aspect. Then, based on established model, the change of interface free energy at different temperatures would be calculated, combining with theoretical calculations of interface binding energy and hydrogen adsorption, dissociation, diffusion and vacancy formation energy, the interaction mechanism of the in-situ transformation of Al3V/AlV3 can be cleared dynamically and thermodynamically. The implementation of this project would significantly improve the dynamic properties and operating temperature of Mg-based hydrogen storage materials, and provide a solid theoretical and experimental basis for the construction of catalyzed continuous shell-coated Mg-based hydrogen storage materials.