Metal nanoparticles incorporated MIL-101(Cr) for enhanced hydrogen storage at room temperature

Abstract

MIL-101(Cr) is considered a potential material for hydrogen (H 2 ) storage, but its H 2 uptake at room temperature was found to be low. However, incorporating metal nanoparticles (MNPs) into the framework helps enhance its H 2 uptake. Platinum (Pt) is the commonly used MNP to increase the H 2 uptake of MIL-101(Cr). However, its higher cost hinders its use for practical applications. Molybdenum (Mo), a transition metal with low cost, was not examined for H 2 uptake. This study aims to investigate the H 2 storage capacity of an MNP (Pt or Mo) incorporated MIL-101(Cr) at room temperature. Towards this, the aforementioned MNPs are incorporated into the MIL-101(Cr) framework using the double solvent method. These synthesized samples were characterized using different tools and examined for their H 2 storage capacity at 25°C up to 70 bar. The results indicate that the Cr/O ratio of a material plays a significant role in H 2 uptake, compared to its structural properties. Owing to the higher Cr/O ratio, the Mo-incorporated MIL-101(Cr) yielded an H 2 uptake of 0.71 wt% at 25°C and 70 bar. The incorporation of Mo-based MNPs enhances the H 2 uptake of the MIL-101(Cr) framework by 32% and 24% at 25°C and 0°C, respectively. This study identifies the Mo as a potential and low-cost alternative to Pt for achieving enhanced H 2 storage at room temperature.