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Based on the combination of experimental measurements and first-principles calculations we report a novel carbon-based catalytic material and describe significant acceleration of the hydrogenation of magnesium at room temperature in the presence of nickel nanoparticles wrapped in multilayer graphene. The increase in rate of magnesium hydrogenation in contrast to a mix of graphite and nickel nanoparticles evidences intrinsic catalytic properties of the nanocomposites explored. The results from simulation demonstrate that doping of the metal substrate and the presence of Stone-Wales defects turn multilayer graphene from being chemically inert to chemically active. The role of the size of the nanoparticles and temperature are also discussed.

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NiPd bimetallic systems were for the first time synthesized by laser electrodispersion (LED) of the Ni77Pd23 alloy target followed by the deposition of produced bimetallic particles on a TEM copper grid and alumina granules. Selective area energy-dispersive analysis confirms the bimetallic nature of NiPd particles deposited on a TEM copper grid. Their mean size is 1.0 nm according to TEM. XPS data demonstrate that under deposition on alumina granules (total metal content of 0.005 wt.%), nickel in bimetallic particles nearly completely oxidizes to Ni2+ species predominantly in the form of aluminate. At the same time major part of palladium (84%) exists in Pd0 but oxidizes to Pd2+ (80%) during 6 months storage in air. Both metals are deposited on the external surface of alumina granules and localized in the same areas. In situ reduction of both metals by H2 in the catalytic cell of XPS spectrometer is hindered. Nickel is not reduced even at 450°C, confirming the formation of NiAlOx, whereas palladium is reduced at higher temperatures compared to a similar monometallic catalyst. Nevertheless, NiPd/Al2O3 catalyst is more efficient in gas-phase chlorobenzene hydrodechlorination at 150–350°C than Ni/Al2O3 and even Pd/Al2O3, and much more stable. The difference may be caused by the formation of new active sites due to the contact between Pd0 and NiAlOx-modified support, and the protective action of spinel reacting with HCl by-product.