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Just shake or stir. About the simplest solution for the activation and hydrogenation of an FeTi hydrogen storage alloy

2021; Elsevier BV; Volume: 47; Issue: 8 Linguagem: Inglês

10.1016/j.ijhydene.2021.11.136

1879-3487

Abhishek Kumar Patel, Dariusz Siemiaszko, Julita Dworecka-Wójcik, Marek Polański,

Ammonia Synthesis and Nitrogen Reduction

Despite many years having passed since it was discovered, FeTi alloys remain one of the most important low-temperature hydrogen storage alloys due to its high capacity, characteristics and low price. However, the main technological issue is its initial activation, which is usually conducted at relatively high temperature and pressure. This paper is the first to show that the complicated process can be replaced by intense movement of the powder or even chunks of alloy under hydrogen pressure without any additional grinding media. The newly discovered process, named self-shearing reactive milling (SSRM), leads to the full hydrogenation of FeTi alloys. The wear of particles, which is caused by their movement, causes the exposure of a fresh active alloy surface that is active enough to absorb hydrogen without any thermal treatment or evacuation. The resultant material, despite simply being strongly stirred, evolves from large chunks to an extremally fine spongy structure containing particle with sizes of tens of nanometers that combine to form large agglomerates. This result is an enormous improvement for the potential use of FeTi alloys and all other AB-type alloys in commercial applications by extraordinarily simplifying hydrogen storage vessels, which will not have to withstand high-temperature and pressure activation.