Chen Gang, Zhang Yao, Chen Jian, Guo Xinli, Zhu Yunfeng, Li Liquan
School of Materials Science and Engineering, Jiangsu Key Laboratory of Advanced Metallic Materials, Southeast University, Nanjing 211189, People's Republic of China.
Nanotechnology. 2018 Jun 29;29(26):265705. doi: 10.1088/1361-6528/aabcf3. Epub 2018 Apr 10.
Nano-dispersed Ni particles over mesoporous carbon material CMK-3 (Ni/CMK-3) was fabricated by means of impregnation-reduction strategy using precursor NiCl · 6HO, which is beneficial to improving the de/rehydrogenation performances of MgH. The dehydrogenation onset temperature of MgH-Ni/CMK-3 is significantly lowered by 170 K from that of pristine MgH (around 603 K). Totally 5.9 wt% of hydrogen absorption capacity is liberated within 1 h at a temperature of 423 K under a pressure of 3 MPa. This composite can absorb 3.9 wt% hydrogen even at a temperature of 328 K under 3 MPa H. Activation energy values of both dehydrogenation (43.4 kJ mol) and rehydrogenation (37.4 kJ mol) for MgH-Ni/CMK-3 are greatly enhanced from those of as-milled MgH. Ni/CMK-3 also slightly destabilizes the dehydrogenation of MgH by 1.5 kJ mol [Formula: see text] The enhanced performances can be attributed to the synergistic effects of both destabilization and activation from nano-dispersed Ni particles.
通过使用前驱体NiCl₂·6H₂O的浸渍还原策略，在介孔碳材料CMK-3上制备了纳米分散的Ni颗粒（Ni/CMK-3），这有利于提高MgH₂的脱氢/再氢化性能。MgH₂-Ni/CMK-3的脱氢起始温度比原始MgH₂（约603K）显著降低了170K。在3MPa压力下，于423K温度下，1小时内总共释放出5.9wt%的吸氢容量。即使在3MPa氢气压力下，温度为328K时，这种复合材料仍能吸收3.9wt%的氢气。MgH₂-Ni/CMK-3的脱氢（43.4kJ/mol）和再氢化（37.4kJ/mol）的活化能值比球磨后的MgH₂有很大提高。Ni/CMK-3还使MgH₂的脱氢稳定性略有降低1.5kJ/mol[公式：见原文]。性能的提高可归因于纳米分散的Ni颗粒的去稳定化和活化的协同效应。
