Work

Solid–State Hydrogen Storage Materials with Excellent Selective Hydrogen Adsorption in the Presence of Alkanes, Oxygen, and Carbon Dioxide by Atomic Layer Amorphous Al2O3 Encapsulation

Year: 2025

Type: article

Abstract: Metal hydrides with high hydrogen density provide promising hydrogen storage paths for hydrogen transportation. However, the requirement of highly pure H 2 for re-hydrogenation limits its wide application. Here, amorphous Al 2 O 3 shells (10 nm) were deposited on the surface of highly active hydrogen storage material particles (MgH 2 –ZrTi) by atomic layer deposition to obtain MgH 2 –ZrTi@Al 2 O 3 , which have been demonstrated to be air stable with selective adsorption of H 2 under a hydrogen atmosphere with different impurities (CH 4 , O 2 , N 2 , and CO 2 ). About 4.79 wt% H 2 was adsorbed by MgH 2 –ZrTi@10nmAl 2 O 3 at 75 °C under 10%CH 4 + 90%H 2 atmosphere within 3 h with no kinetic or density decay after 5 cycles (~ 100% capacity retention). Furthermore, about 4 wt% of H 2 was absorbed by MgH 2 –ZrTi@10nmAl 2 O 3 under 0.1%O 2 + 0.4%N 2 + 99.5%H 2 and 0.1%CO 2 + 0.4%N 2 + 99.5%H 2 atmospheres at 100 °C within 0.5 h, respectively, demonstrating the selective hydrogen absorption of MgH 2 –ZrTi@10nmAl 2 O 3 in both oxygen-containing and carbon dioxide-containing atmospheres hydrogen atmosphere. The absorption and desorption curves of MgH 2 –ZrTi@10nmAl 2 O 3 with and without absorption in pure hydrogen and then in 21%O 2 + 79%N 2 for 1 h were found to overlap, further confirming the successful shielding effect of Al 2 O 3 shells against O 2 and N 2 . The MgH 2 –ZrTi@10nmAl 2 O 3 has been demonstrated to be air stable and have excellent selective hydrogen absorption performance under the atmosphere with CH 4 , O 2 , N 2 , and CO 2 .

Source: Nano-Micro Letters

DOI: 10.1007/s40820-025-01934-7