Hydrogen from nickel

It had been found that removal of hydrogen from nickel at 350°C, instead of at room temperature, produced a profound difference in the properties of the nickel with respect to ethylene chemisorption (4). Therefore the chemisorption of carbon monoxide was repeated using nickel which had been degassed at 350°C. This produced a startling difference compared to the results shown in Fig. I now most of the carbon monoxide was chemisorbed in the linear structure (5). Similar experiments have not been made with palladium but it is reasonable to predict that the ratio of linear to bridged carbon monoxide would be increased by a more thorough removal of hydrogen from this metal. 

Euringer (24), who measured the evolution of hydrogen from nickel wires, gave a method for measuring both the solubility and the diffusion constant. The method, which should be of general applicability, was based upon the following solution of Tick s law (Chap. I) ... 

Euringer(24) employed the method described on p. 214 to interpret his results on the desorption of hydrogen from nickel. He obtained the values for D = given in... 

Appreciable quantities are also obtained as a by-product in the manufacture of hydrogen from naphtha-gaseous hydrocarbons. In this process the gaseous hydrocarbon and superheated steam under a pressure of about 10 atmospheres and at a temperature of 1000 K are passed over a nickel-chromium catalyst. Carbon monoxide and hydrogen are produced ... 

In metallurgy, hydrogen sulfide is used to precipitate copper sulfide from nickel—copper-containing ore leach solutions in Alberta, Canada, or to precipitate nickel and cobalt sulfides from sulfuric acid leaching oflaterite ores in Moa Bay, Cuba (120) (see Metallurgy, extractive metallurgy). 

In normal battery operation several electrochemical reactions occur on the nickel hydroxide electrode. These are the redox reactions of the active material, oxygen evolution, and in the case of nickel-hydrogen and nickel-metal hydride batteries, hydrogen oxidation. In addition there are parasitic reactions such as the corrosion of nickel current collector materials and the oxidation of organic materials from separators. The initial reaction in the corrosion process is the conversion of Ni to Ni(OH)2. 

Fig. 3. Isotherm pm = /(H/Ni) at 25°C obtained during hydrogen desorption from nickel foil saturated with hydrogen. After Baranowski and BocheAska (11a).

Several other important commercial processes need to be mentioned. They are (not necessarily in the order of importance) the low pressure methanol process, using a copper-containing catalyst which was introduced in 1972 the production of acetic add from methanol over RhI catalysts, which has cornered the market the methanol-to-gasoline processes (MTG) over ZSM-5 zeolite, which opened a new route to gasoline from syngas and ammoxidation of propene over mixed-oxide catalysts. In 1962, catalytic steam reforming for the production of synthesis gas and/or hydrogen over nickel potassium alumina catalysts was commercialized. 

Marino, F. J. Cerrella, E. G. Duhalde, S. Jobbagy, M. Laborde, M. A., Hydrogen from steam reforming of ethanol. Characterization and performance of copper-nickel supported catalysts. International Journal of Hydrogen Energy 1998,23(12), 1095-1101. 

Hydrogen.—The olefines cannot be hydrogenated with nascent hydrogen from any of the usual reducing agents. The reduction only succeeds catalytically with hydrogen in the presence of finely divided metals, such as nickel (Sabatier), palladium (Paal, Skita), or platinum (Fokin, Willstatter). Cf. the preparations on pp. 376 ff. 

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