High‐Temperature Hydrogen Adsorption Properties of Precursor‐Derived Nickel Nanoparticle‐Dispersed Amorphous Silica

Nickel (Ni) nanoparticle‐dispersed amorphous silica (Si–O) powders were synthesized from chemical solution precursors. The high‐temperature hydrogen adsorption property of the precursor‐derived composite powders was investigated in comparison with the amorphous Si–O and Ni at 773 K. Among the three powder samples, Ni nanoparticle‐dispersed amorphous Si–O exhibited a unique reversible hydrogen adsorption property that was hardly detected on the amorphous Si–O and Ni. The increase amount of the reversibly adsorbed hydrogen was the highest for the composite samples at around the Ni content with a Ni/(Si+Ni) ratio of 0.2–0.3. The results strongly suggested that when the composite material is used in the form of a gas separation membrane, the reversibly adsorbed hydrogen property is thought to contribute to the additional increase in the number of solubility sites for hydrogen, which leads to a selective enhancement in the high‐temperature hydrogen permeance at 773 K.