Preparation of Pt particles dispersing nanocomposites by thermal treatment of tetrachloroplatinate/layered double hydroxide (LDH)

Mg-Al LDH intercalated PtCL₄^2- anion (PtCl ₄-LDH) was synthesized by a reconstruction method using potassium tetrachloroplatinate and its thermal changes were investigated at various temperatures. The PtCl₄-LDH included 17 mass% Pt was synthesized by a reconstruction method using K₂PtCl₄ solution of 10 mM to adjust the pH with NaOH to about 11. The obtained PtCl₄-LDH shows high crystallinity and has low content of CO₃^2-. The basal spacing of the obtained PtCl₄-LDH was 0.83 nm expanding slightly from 0.78 nm of starting LDH. The XRD patterns of the obtained PtCl ₄-LDH showed that the second 001 diffraction line (006) became more accentuated than the first one (003) according to the intercalation of Pt components. Pt fine particles in the several nm were directly observed by TEM after firing at 500°C. However, the diffraction patterns of Pt or Pt components were not detected via XRD in the same sample. This is due to the coagulation of Pt components by the narrow basal spacing of the PtCl4-LDH.