An NMR study on the effect of water on hydrogen storage in palladium silica material (Pd/MCM-41)

We report a simple method of entrapping hydrogen gas inside palladium silica material (Pd/MCM-41). Nuclear Magnetic Resonance spectroscopy shows water can be used as a simple mechanism for entrapping and releasing hydrogen gas in this material. For dry samples of Pd/MCM-41 loaded with hydrogen gas at 2 atm, the 1 H-NMR gas signal continued to attenuate and eventually disappeared after approximately 17 min. In contrast, adding water to a dry sample of Pd/MCM-41 loaded with hydrogen gas entrapped the hydrogen into the sample. In this case, the 1 H-NMR signal of the gas remains unchanged for up to a week. In addition, removing the water caused the hydrogen gas to start leaving the material. This is an essential step toward finding an easy way to store/release hydrogen gas at pressures close to the atmospheric value in metallic based porous materials.