Hydrogen storage performance of a nanoporous activated carbon cloth-like material doped by palladium

Extensive research has been carried out in the field of materials-based H₂ storage during the last two decades, where nanoporous and high-surface area carbons are studied as efficient sorbent materials for physical adsorption and confinement of H₂ inside their porous structure. However, these carbons are usually produced as loose and fine powders, thus creating technical issues regarding their safe handling and large-scale implementation in H₂ storage systems for stationary and mobile applications. Herein, a pure carbon material in cloth-like form, with large specific surface area (~1200 m²/g) and pore volume (~0.5 cm³/g) as well as narrow ultra-micropore sizes (~0.6 nm), was produced via carbonization and CO₂ activation of a cellulose-based polymer (viscose rayon cloth). The H₂ cryo-adsorption behavior was fully reversible at temperatures below 100 K and a significant H₂ gravimetric uptake of ~3.10 wt.% was recorded at 77 K and ~60 bar. However, the equivalent performance at 298 K was rather poor (< 0.2 wt.%) and not sufficient for practical applications. Therefore, the carbon cloth material was doped with magnetron sputter deposited Pd with the intention to enhance the carbon surface-molecular H₂ interaction at room temperature. The outcome of this novel approach is discussed in detail.