Zhang Yan, Wu Fuying, Guemou Samuel, Yu Haijie, Zhang Liuting, Wang Yijing
School of Energy and Power, Analysis and Testing Center, Jiangsu University of Science and Technology, Zhenjiang 212003, China.
Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), College of Chemistry, NanKai University, Tianjin, 300071, China.
Dalton Trans. 2022 Nov 1;51(42):16195-16205. doi: 10.1039/d2dt02090d.
Herein, an active positive electrode material, LiCoO nanosheets, was synthesized a two-step method, which demonstrated a remarkable catalytic effect for the hydrogen storage property of MgH. Incorporated with LiCoO nanosheets, MgH started to release hydrogen at 180 °C and a desorption content as high as 5.5 wt% H was attained within 60 min at 250 °C. The dehydrogenation activation energy was significantly decreased to 48.5 ± 0.4 kJ mol, achieving a 68.9% reduction compared to MgH. It was verified by microstructural studies that Li served as an "anchor" to facilitate a uniform distribution of LiCoO "boat" among the MgH "ocean", benefitting the self-assembly of numerous MgCo-MgCoH couples on the surface of MgH during the cycling process. Meanwhile, the formed MgCo-MgCoH couples were not restricted to offering multiple channels for fast hydrogen diffusion but also worked as "nano hydrogen pumps" to accelerate Mg/MgH hydrogen charging and discharging. This study provides an interesting example of effective cooperation between Li and Co on improving the catalytic action toward MgH. It shall shed light on efficient designing of high-efficient catalysts in hydrogen storage areas or other energy-related fields.
在此，通过两步法合成了一种活性正极材料LiCoO纳米片，其对MgH的储氢性能表现出显著的催化作用。与LiCoO纳米片结合后，MgH在180℃开始释放氢气，在250℃下60分钟内达到高达5.5 wt% H的解吸量。脱氢活化能显著降低至48.5±0.4 kJ/mol，与MgH相比降低了68.9%。微观结构研究证实，Li作为“锚”，促进了LiCoO“船”在MgH“海洋”中的均匀分布，有利于在循环过程中在MgH表面自组装大量的MgCo-MgCoH对。同时，形成的MgCo-MgCoH对不仅为快速氢扩散提供了多个通道，还作为“纳米氢泵”加速Mg/MgH的氢充放电。本研究提供了一个Li和Co在改善对MgH的催化作用方面有效合作的有趣例子。它将为储氢领域或其他能源相关领域高效催化剂的高效设计提供启示。
