ИСТИНА

The method for the formation of metal-carbon catalysts with VIII group metals nanoparticles, fixed on detonation nanodiamonds (DND), for steam reforming of ethanol was developed. DND as the support for ethanol steam reforming catalysts are observed for the first time. Formation of metal-carbon catalyst occurs via IR pyrolysis of precursor. The compositions based on compounds of Pd, Ni, Ru (dissolved in DMFA) and DND were employed as the precursors. The sources of metals were Pd (CH3COO)2, NiCl2, RuCl3. IR pyrolysis of precursor was carried out in a pulse photon annealing laboratory device at 700 °C. The formation of chelate between metal ions and ether bonds presented on the surface of DND was shown with IR Fourier spectroscopy for nanocomposite DND/NiCl2 which was taken as example. The distribution of metal particles was studied by transmission electron microscopy. It was shown that metal particle size depended on metal concentration in the precursor. Thus there were only very small metal particles (about 0.5–1.5 nm) in DND/Pd-Ru(1%). And there were both types of nanoparticles in DND/Pd-Ru(20%): 1 nm and 15-20 nm. The X-ray diffraction showed that there are reduced metals in the prepared nanocomposite for nanocomposites (for example DND/Pd and DND/Pd-Ru were taken). There were an alloy nanoparticles in the nanocomposite in case of the presence of two metals in the precursor. The calculations of the structural characteristics of the metallic phase in nanocomposites were performed. And the Pd-Ru alloy is very similar to the intermetallic compound Pd9Ru. Applying metal-carbon nanocomposite DND/Pd as heterogeneous catalyst in the reaction of steam reforming of ethanol caused considerable increase of ethanol conversion from 60 up to 90% in the temperature range 400–600 °C. The highest yield of hydrogen was achieved at 600 °C and it was 1.83 mol H2/ mol EtOH. The catalyst DND/Pd-Ru was proved to be more effective than DND/Pd. The catalyst DND/Pd-Ru showed almost total conversion of the ethanol at temperature above 500 °C.