In this paper, it shown that due to the size effect, we can create a catalytically active system based on gold nanoparticles. Gold, considered not so long ago, an inert metal, the transition in nanodispersed condition begins to show high catalytic activity in the reaction of ortho-para hydrogen conversion. It is shown that gold particle size from 1 nm to 40 nm possess high specific catalytic activity, which does not depend on the particle diameter in the size range. The assumption made that the hydrogen conversion proceed on magnetic mechanism, and, consequently, the gold particles become the new magnetic properties in comparison with diamagnetic massive metal.

Gold films are obtained by thermal evaporation in different media: vacuum, hydrogen, and krypton. The structure of the films obtained, and their adsorption and catalytic properties in molecular hydrogen reactions are studied in a wide temperature range. It is found that gold films with a special structure can adsorb hydrogen and exhibit catalytic activity in reactions with molecular hydrogen under cryogenic conditions. Differences in the structure and catalytic properties of the gold films depending on the preparation conditions are shown.

Adsorption and catalytic properties of gold nanoparticles of various sizes prepared by two methods of reduction in reverse micellar solutions were studied. Gold nanoparticles are capable of adsorbing molecular hydrogen and exhibiting catalytic activity in reactions of ortho—para conversion of protium and deuterium—hydrogen exchange. The size dependence of the catalytic activity of gold nanoparticles in reaction of H2—D2 exchange regardless of the method of preparation was determined.

The adsorptive and catalytic properties of gold nanoparticles, prepared in reverse micelles solutions by chemical reduction and deposition on γ-Al2O3 were studied. As model reaction H2 + D2 = 2HD was used. In contrast to bulk gold, catalytic activity of gold nanoparticles has been found.

Gold nanoparticles of 3.8, 4.6, and 19.4 nm size, unlike the bulk metal, can adsorb hydrogen and catalyze the deuterium—protium exchange in the 77—523 K range. It has been shown that as the particle size decreases, the specific catalytic activity increases. The exceptionally high catalytic activity of gold nanoparticles in the ortho—para hydrogen conversion with respect to the deuterium—hydrogen exchange may indicate that at low temperatures the nanoparticles exhibit magnetic properties.

It has been established that the size of metal nanoparticles affects the adsorption properties and catalytic activity of deposited palladium catalysts used in H2-D2 exchange reactions and ortho-para protium conversion reactions. Nanoparticles have been obtained by radiation-chemical reduction from reversemicellar solutions. The structure and size of the prepared palladium nanoparticles have been studied.