Individual nanoparticles of aluminum, gold, nickel, and platinum deposited on a pyrolytic graphite surface

Hydrogenation of HOPG-supported Gold Nanoparticles: Features of Initial Stages

“…Thus, the results of quantum chemical calculations correlate with results of the above experiment, which together demonstrate that at small exposures of HOPG-supported gold nanoparticles to deuterium, adsorption occurs predominantly on the periphery of gold nanoparticles close to the gold-carbon interface. In addition, our calculations prove the conclusions of [20,21], where hydrogen adsorption on HOPG-supported gold nanoparticles was shown to decrease local conductivity of tunnel nanocontact.…”

“…Note that the difference in the adsorption energy at the interface and at the top is small (i.e., the surface migration of D adatoms is constrained because of a significant activation barrier). Existence of this barrier was confirmed experimentally in our previous work [20], where we described strong bonding between hydrogen and gold nanoparticles on the surface of graphite and the long transition time (up to 25-30 h) of the system to the final (stationary) state. Of course, the real values of binding energy are likely to be significantly lower than the calculated ones, which is at least partly due to the absence of the correction of basis set superposition error, but such comparison of calculated values is valid.…”

“…As a result, the layer of adsorbed H atoms is unstable. However, experimentation on hydrogen interaction with gold nanoparticles given in this paper and other works [20,[29][30][31] demonstrates the existence of a fairly stable form of hydrogen adsorption. How can these results be explained?…”

“…In [19] it was suggested that hydrogen dissociation occurs on low-coordinated gold atoms, then hydrogen atoms migrate to the substrate. In our previous works [20,21], using methods of scanning tunneling microscopy (STM) and spectroscopy (STS), we observed the dissociative adsorption of hydrogen on gold nanoparticles deposited on graphite. Thus, direct participation of gold nanoparticles in the processes of molecular hydrogen dissociation is not in doubt.…”

Nanostructured composites based on highly porous carbon matrices filled with gold

“…The combinations of features of optical, catalytic, electrophysical, electrochemical, and other properties of the components (metals and carbon matrices) in nanosized state are expected to be clearly manifested in these systems, which can broaden the range of functional parameters and the scope of application of materials based on them. NMCC are currently used to manufacture electrode materials and catalysts for various chemical processes [1,2]. The production of gold-containing composites is rather promising, since gold can form ultrathin conductive oxidation-resistant films on the surface of substrates (graphite, grapheme, fullerenes, nanodiamond, carbon fibers, and nanotubes, as well as oxide matrices, especially mesoporous ones [3,4]) that exhibit unique electrophysical, optical, catalytic, and other properties.…”