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

Mg-Al LDH intercalated PtCl42- anion (PtCl4-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 CO32-. 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 PtCl4-LDH showed that the second 00l 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.