Nickel-Copper catalysts

Other metal oxide catalysts studied for the SCR-NH3 reaction include iron, copper, chromium and manganese oxides supported on various oxides, introduced into zeolite cavities or added to pillared-type clays. Copper catalysts and copper-nickel catalysts, in particular, show some advantages when NO—N02 mixtures are present in the feed and S02 is absent [31b], such as in the case of nitric acid plant tail emissions. The mechanism of NO reduction over copper- and manganese-based catalysts is different from that over vanadia—titania based catalysts. Scheme 1.1 reports the proposed mechanism of SCR-NH3 over Cu-alumina catalysts [31b],... 

Fig. 8. The adsorption of hydrogen on copper-nickel catalysts as a function of the copper content. The circles represent the total amount of hydrogen adsorbed at room temperature at 10-cm pressure. The triangles represent the amount of strongly adsorbed hydrogen, i.e., the amount not removed by a 10-min evacuation at room temperature following the completion of the initial adsorption isotherm. The amount of strongly adsorbed hydrogen is determined as the difference between the initial isotherm and a subsequent isotherm obtained after a 10-min evacuation (74).

Five main types of CNFs, platelet (P-CNF), tubular (T-CNF), thick herringbone (thick FI-CNF), thin herringbone (thin H-CNF) and very thin herringbone (very thin FI-CNF) vere selectively prepared and examined as supports of anode catalysts for DMFCs. P-CNF was synthesized from carbon monoxide over a pure iron catalyst at 600 °C, whereas thick H-CNF was obtained from ethylene over a copper-nickel catalyst [Cu-Ni (2 8 w/w)]. An Fe-Ni alloy (6 4 w/w) was used for the selective synthesis of T-CNFs from carbon monoxide gas at 650 °C [15, 16]. 

In the direct reaction of //-hexyl chloride, a 1 4 gaseous mixture of //-hexyl chloride and hydrogen chloride reacted with elemental silicon in the presence of copper/nickel catalyst at 280 °C to give the corresponding //-hexyl-containing chlorosilanes, /z-hexyldichlorosilane (30%) and /z-hexyltrichlorosilane (11%), along with 1-hexene (22%) (Eq. 9).83... 

Vedenyapin, A.A., Chankvetadze, B.G., and Klabunovskii, E.L (1984) Studies of Copper- Nickel catalysts for enantioselective hydrogenation. React. Kinet Catal. Letters 24,77-80. 

Areshidze, G.Kh. (1976) Studies of phase composition, adsorption, catalytic and as5mimetric properties of copper-ruthenium and copper-nickel catalysts, Cand. Diss.Thesis, N.D. Zelinskii Institute of Organic Chemistry, Academy of Sciences of the USSR, Moscow (supervisors Klabunovskii, E.l and Vedenyapin, A. A ). 

Thermogravimetric analysis of the copper/nickel catalyst clearly indicates a significant difference from the original nickel catalyst ... 

The copper/nickel catalyst contains more residual hydrate, hydroxyl and carbonate than the nickel catalyst. 

Undecomposed copper/nickel catalyst reduces very easily in hydrogen with two distinct reduction peaks. The first, between 180-280 C, corresponds to the reduction of free nickel and copper oxides. The second, between 240 50°C, corresponds to the single r uction peak of nickel catalyst. 

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