基于核壳结构Ni/Co@C复合镁基储氢材料的吸放氢动力学性能研究

Mg-based hydrogen storage materials show high hydrogen storage density and low cost, but its practical application is hindered by its high sorption/release temperature and poor kinetics performance. In view of this, the project intends to synthesize highly active core-shell Ni@C and Co@C catalysts through low-temperature solid-phase reaction and microwave assisted liquid technology to achieve its fabrication. Benzimidazole will be used as ligand and carbon source. Its size, morphology, activity and thickness of shell will be controlled by means of optimizing synthetic conditions (cobalt/nickel source, ligand type, coordination number, etc.). Ni/Co@C-MgH2 system will be constructed by controlling the co-growth of Ni@C and Co@C with MgH2 to achieve kinetics properties regulation and improvements of hydrogen storage properties, thereby decreasing hydrogen sorption/release temperature. The influences of structure, morphology and size of different catalysts on the hydrogen storage process of Mg-based materials will be investigated on the micro-level. The rate control steps and reaction mechanism during the reaction process will be further investigated. Besides, we focus on the regulation about the activation energy of hydrogen sorption/release. Finally, finding ways to improve the hydrogen storage stability and cycle life that can provide the foundation for energy efficient transmission. This project will provide theoretical basis for further practical application of Mg-based hydrogen storage materials.

镁基储氢材料具有储氢密度高和价格低廉等优点，但是其较高的吸放氢温度、较差的动力学性能，阻碍了其实际应用。针对上述问题，本项目拟采用低温固相、微波辅助液相等方法实现高活性核壳结构Ni@C和Co@C催化剂的微纳制备，以苯并咪唑等作为配体和碳源，通过合理调节钴/镍源、配体种类、配位个数等条件，对催化剂尺寸、形貌和催化活性进行调控。控制其与MgH2的复合生长，构筑Ni/Co@C-MgH2复合储氢体系，实现储氢材料的动力学性能调控，从而降低吸放氢温度，提高吸放氢速率，改善储氢性能。从微观层次探讨不同催化剂的结构、颗粒形貌和尺寸等对复合镁基储氢体系吸放氢过程的影响规律，阐明Ni/Co@C-MgH2的吸放氢速率控制步骤和反应机理，注重材料储氢过程中活化能的分析，寻找提高储氢稳定性和循环寿命的途径，为能量的高效传递提供基础。本项目有助于为Mg基储氢体系的实际应用提供理论基础。

镁基储氢材料具有储氢密度高和价格低廉等优点，但是其较高的吸放氢温度、较差的动力学性能，阻碍了其实际应用。本项目提出采用低温固相等方法实现高活性Ni@C和Co@C催化剂的制备，并将其作为催化剂改善了MgH2储氢性能的技术方案。. 本项目采用低温固相方法，以苯并咪唑作为配体和碳源，实现了高活性核壳结构Ni@C和Co@C催化剂的微纳制备。通过控制其与MgH2的复合生长，构筑了Ni/Co@C-MgH2复合储氢体系，实现储氢材料的动力学性能调控，从而降低吸放氢温度，提高吸放氢速率，改善储氢性能。从微观层次探讨了不同催化剂、颗粒形貌和尺寸等对复合镁基储氢体系吸放氢过程的影响规律，阐明了Ni/Co@C-MgH2的吸放氢速率控制步骤和反应机理，并对材料储氢过程中的活化能进行了详细分析。