Lu Yanshan, Asano Kohta, Schreuders Herman, Kim Hyunjeong, Sakaki Kouji, Machida Akihiko, Watanuki Tetsu, Dam Bernard
Energy Process Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba West, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan.
Hydrogen Energy Research Center, Guangzhou Power Supply Bureau, Guangdong Power Grid Company Limited, Guangzhou, Guangdong 510620, China.
Inorg Chem. 2021 Oct 4;60(19):15024-15030. doi: 10.1021/acs.inorgchem.1c02525. Epub 2021 Sep 20.
Phase segregation in hydride-forming alloys may persist under the action of multiple hydrogenation/dehydrogenation cycles. We use this effect to destabilize metal hydrides in the immiscible Mg-Mn system. Here, in the MgMn thin films, the Mg and Mn domains are chemically segregated at the nanoscale. In Mn-rich compositions, the desorption pressure of hydrogen from MgH is elevated at a given temperature, indicating a thermodynamic destabilization. The increase in the desorption pressure of hydrogen reaches ∼2.5 orders in magnitude for = 0.30 at moderate temperatures. Such large thermodynamic destabilization allows the MgH to reversibly absorb and desorb hydrogen even at room temperature. Our strategy to use immiscible elements for destabilization of MgH is effective and opens up the possibility for the development of advanced and low-cost hydrogen storage and supply systems.
在形成氢化物的合金中，相分离可能会在多次氢化/脱氢循环的作用下持续存在。我们利用这种效应来使不混溶的Mg-Mn系统中的金属氢化物不稳定。在这里，在MgMn薄膜中，Mg和Mn域在纳米尺度上发生化学分离。在富Mn成分中，在给定温度下，MgH中氢的解吸压力升高，表明热力学不稳定。在中等温度下，对于 = 0.30，氢解吸压力的增加达到约2.5个数量级。如此大的热力学不稳定使得MgH即使在室温下也能可逆地吸收和解吸氢。我们使用不混溶元素使MgH不稳定的策略是有效的，并为开发先进且低成本的储氢和供氢系统开辟了可能性。
