Preparation, structure and stability of highly dispersed Ni on vitreous supports

The preparation of Ni dispersions on vitreous supports has been undertaken by reacting Ni(C3H5)2 with the surface -OH groups of the support (chemical composition: 71% SiO2, 18% Al2O3, 11% Na2O) and reducing the anchored species with H2. The preparation method and the smallness of the support pores lead to very high Ni dispersions. The catalyst with low Ni metal percentage, and particle dimensions smaller than 30 Å, is not useful for hydrogenation reactions since it is degraded by the presence of H2. This phenomenon is demonstrated and discussed in terms of the stability and chemical reactivity of extreme metal dispersions.