Isotope tracer studies of the variability in the physical and chemical properties of nickel/silica catalysts as a function of the silica support

• Published in: Catalysis today 1991-09, Vol.10 (3), p.323-328
• Main Authors: Jackson, S.D., Jones, J.R., Sharratt, A.P., Gladden, L.F., Vignaux, M., Robertson, F.J., Webb, G., Cross, R.J., Griffiths, R.W.
• Format: Article
• Language: English
• ISSN: 0920-5861; 1873-4308
• DOI: 10.1016/0920-5861(91)80012-X

Two 1% nickel/silica catalysts have been prepared, by aqueous and non-aqueous impregnations of nickel nitrate, on a silica support (PQ CS2040). This silica is unstable with respect to pore contraction in aqueous media and hence allowed a comparison to be made of physically distinct supports of identical chemical composition. The activity of the catalysts for ethene hydrogenation was studied using samples reduced in [ 3H]hydrogen: two methods of treating the catalysts were used. After reduction in [ 3H]hydrogen, the catalyst was flushed with helium at 723 K until no radioactivity could be detected in the exit gas, then cooled to 293 K in flowing helium. In the second method the catalyst was cooled to 293 K in [ 3H]hydrogen before flushing with helium. Ethene was pulsed over the samples and the incorporation of [ 3H]hydrogen in the ethene, ethane and methane monitored at various temperatures. A relationship was observed between the degree of incorporation and the structure of the silica supports.