Nickel on graphite

Nickel-Graphite. A highly dispersed nickel on graphite (Ni-Gr 1) is obtained by reduction of NiBr2 2DME dissolved in THF HMPT (15 1) with CSK (2 equiv.) at 20° under argon. This material is slowly oxidized by air to give a less active metal (Ni-Gr 2), which can be stored for several months. 

In the Auger spectra of the supported catalysts, the carbon peak at 272 eV, with the characteristic shape of graphite did not present any fine structure at lower energy, which would indicate a strong interaction between nickel and graphite as shown previously during deposition of nickel on graphite by CVD [6]. 

Umani-Ronchi and his co-workers have prepared various new active metals that consist of highly dispersed palladium or nickel on graphite and which selectively catalyse the semi-hydrogenation of acetylenes to Z-olefins. A different catalyst for the same process can be prepared by successive treatment of chloromethylated polystyrene beads with anthranilic acid and palladium chloride. Alternatively, acetylenes can be reduced to Z-oIefins by a catalytic transfer process using sodium phosphinate as the hydrogen donor and an easily prepared lead- or mercury-modified palladium catalyst. ... 

Lead dioxide on graphite or titanium substrates has been utilised as an anode in the production of chlorate and hypochlorites and on nickel as an anode in lead-acid primary batteries Lead dioxide on a titanium substrate has also been tested for use in the cathodic protection of heat exchangers and in seawater may be operated at current densities up to lOOOAm" . However, this anode has not gained general acceptance as a cathodic protection anode for seawater applications, since platinised Ti anodes are generally preferred. 

The XRD for the sample of Ni-metallized on graphite (4.6wt%) is provided in Fig. 2c, however the strongest peaks of Ni metal are overlapping with those peak reflections from the MAG-10 graphite. But, the X-ray diffraction in Fig. 2a revealed the Ni particles were pure nickel crystalline with a face-centered cubic (fee) structure. 

Batley and Matousek [390,778] examined the electrodeposition of the irreversibly reduced metals cobalt, nickel, and chromium on graphite tubes for measurement by electrothermal atomisation. This method offered considerable potential for contamination-free preconcentration of heavy metals from seawater. Although only labile metal species will electrodeposit, it is likely that this fraction of the total metal could yet prove to be the most biologically important at the natural pH [779]. 

Methods for oxidative transformations continue to receive attention. Nickel peroxide on graphite oxidizes geraniol to citral in 89% yield. Three groups report " the oxidative rearrangement of tertiary vinyl carbinols. Linalool is con-... 

The preparation of nickel oxide deposits with high surface area on steel, nickel, copper, graphite or titanium electrodes partly for anodic oxidation of organic compounds and the preparation of pressed nickel oxide powder electrodes mainly for application in storage batteries is described. The performance of nickel oxide anodes for batteries is improved by addition of cobaltflljhydroxide... 

HYDROGENATION, CATALYSTS Nickel on alumina. Nickel-Graphite. Palladium-Poly(ethylenimine). Palladium catalysts. Raney nickel. Rhodium catalysts. 

It has been demonstrated that STM can operate not only in vacuum but also in air [37] and in electrolytes [38]. For example, Sonnenfeld et al. [37] monitored the in situ deposition of silver on graphite and Arvia et al. [39] monitored the effect of repetitive potential cycling on gold. On the other hand, Fan and Bard [40] studied the in situ STM measurements for the corrosion of stainless steel and the dissolution of nickel under potentiostatic conditions. Szklarczyk and Bockris [41] have published an account of the potential dependence of the crystal reconstruction on platinum in the sodium perchlorate solution at the angstrom scale. The atomic lattice of Al( 111) has been reported... 

We prepared Ni-M (M = Al, Cr, Cu, Co and Mo) catalysts supported on graphite, at low temperature, by coreduction of metal salt mixtures (NiXa, MX2) deposited on this support with sodium naphthalene as reducting agent. Quantitative microanalyses performed by STEM/EDX showed that the two metals were evenly distributed over graphite leaflets. The activity and the selectivity of these catalysts in the hydrogenation of citral to citronellal and citronellol have been compared with that of unsupported bimetallic catalysts, with the same atomic composition and prepared by the same procedure. It appeared that the nickel surface area of the supported catalysts was notably higher than that of the unsupported ones, but the support had almost no effect on the catalytic properties. 

Metal salt mixtures (NiXa, MXn) deposited on graphite can be reduced with naphthalene sodium into bimetaiiic supported cataiysts. The process aiiows one to prepare cataiysts with metals as highly reducible as aluminium at low temperature. It is important to notice that the nickel surface area of supported Ni-M catalysts is always larger ( up to seven times ) than that of the unsupported ones prepared by the same procedure. 

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