Nanostructured carbons modified with nickel as potential novel reversible hydrogen storage materials: Effects of nickel particle size

Abstract

In this study, ordered mesoporous carbons CMK-3 were prepared by a nanocasting method using SBA-15 silica as template and sucrose as carbon source. The pure CMK-3 was modified with nickel by wet impregnation method and the effects on hydrogen storage capacity were studied at different pressures and temperatures. The structural, textural and chemical properties were evaluated in order to investigate their correlation with hydrogen adsorption properties. Also, computational methods (DFT) contributed to the understanding of hydrogen storage interactions in the Ni/C samples. Two different behaviors on the hydrogen adsorption were obtained after reduction treatment under H2 atmosphere. For the unreduced samples at 77 K, the textural properties were the determining factor in the H2 storage capacity. On the other hand, for the reduced samples at room temperatures, the presence of nickel nanoparticles increased the hydrogen adsorption, with a possible dependence of the particle size.