The influence of the parameters of the deposition−precipitation method used to prepare Ni/SiO2 samples on
the size of nickel metal particles was investigated by temperature-programmed reduction, transmission electron
microscopy, and thermogravimetry. The results show that the average metal particle size, which varies between
27 and 79 Å, depends on the nature and the reducibility of the supported Ni(II) phase (nickel hydroxide or
1:1 nickel phyllosilicate), and on the extent of the interface between the supported Ni(II) phase and silica.
These parameters themselves depend on the characteristics of the silica support (surface area and morphology)
and on the preparation parameters (urea and silica concentrations). At the interface, a nickel phyllosilicate is
detected whatever the nature of the supported Ni(II) phase. The metal particles are smaller and the size
distribution is narrower when the supported phase is a 1:1 nickel phyllosilicate (d̄ ≤ 50 Å, 10−100 Å) than
when it is a nickel hydroxide (d̄ ≈ 80 Å, 20−280 Å). The metal particles are smaller when the extent of the
Ni(II) phase−silica interface increases. This arises from the comparison of Ni/SiO2 samples prepared from
silicas of high and low surface area, and from nonporous and porous silica.