Supported Metal Particles from LDH Nanocomposite Precursors: Control of the Metal Particle Size at Increasing Metal Content

A family of nanocomposites formed by intercalation of negatively charged Ni-based nanoparticles in Mg/Al layered double hydroxide (LDH) has been prepared by following the anion exchange route. The composites differ by the amount of loaded Ni entities. Suspensions of Ni nanoparticles have been priorily prepared by controlled hydroxylation of Ni 2+ cations in the presence of citrate complexing ions. Intercalated Ni complex colloids exhibit the same behavior in the different composites upon reduction. The nanocomposite route leads after reduction at 1023 K to controlled amounts of metal Ni nanoparticles presenting a similar mean size of 5 nm and a high degree of dispersion on a magnesium/aluminum oxide matrix.