The quality assurance of hydrogen fuel for mobile applications is assessed by the guidelines and directives given in the European and international standards. However, the presence of impurities in the hydrogen fuel, in particular nitrogen, water, and oxygen, is experienced in several refueling stations. Within this work, metal-organic framework (MOF)-based membranes are investigated as a fine-purification stage of the hydrogen fuel. Three H₂/N₂ concentrations have been used to analyze the separation factor of UiO-66-NH₂ membranes prepared using the layer-by-layer (LBL) and the one-pot (OP) synthesis methods. It is shown that the separation factor for an equimolar ratio is 14.4% higher for the LBL sample compared to the OP membrane, suggesting a higher orientation and continuity of the LBL surface-supported metal-organic framework (SURMOF). Using an equimolar ratio of H₂/N₂, it is shown that selective separation of hydrogen over nitrogen occurs with a separation factor of 3.02 and 2.64 for the SURMOF and MOF membrane, respectively. To the best of our knowledge, this is the highest reported performance for a single-phase UiO-66-NH₂ membrane. For higher hydrogen concentrations, the separation factor decreases due to reduced interactions between pore walls and N₂ molecules.

The potential to control the structure of amorphous materials and establish correlations with their properties would constitute an extraordinary step in formulating new pathways to design and tailor amorphous structures, which correspondingly would exhibit novel properties. Towards achieving this goal, a bottom-up approach is proposed here. In the present study, cluster-assembled Fe₈₀Sc₂₀ metallic glasses are used as the model systems to illustrate this potentially groundbreaking approach. Accordingly, Fe₈₀Sc₂₀ amorphous films are nanofabricated under well-defined conditions with precise control over cluster size and impact energy. Their local atomic structures are characterized by X-ray absorption spectroscopy around both constituent metals, i.e., Fe and Sc. The capability of controlling the local structure by controlling the deposition energy (i.e., the clusters’ impact energy) has resulted in substantial changes in the magnetic Curie temperature. In fact, the Curie temperature changes by as much as 60 K when the deposition energy is increased from 50 eV per cluster (the lowest deposition energy) to 500 eV per cluster (the highest deposition energy). This remarkable result, clearly establishing a structure–property relationship, observed for the first time in cluster-assembled metallic glasses, opens up new pathways for synthesizing novel amorphous materials with engineered structures and accompanying new properties.