Formation of porous structure via catalytically promoted decomposition of hydrotalcites intercalating hexachloroplatinate

Thermal decomposition of platinum hexachloroplatinate (PtCl62−)-intercalated hydrotalcite (HT)-like solid, Mg0.74Al0.26(OH)2(NO3)0.26, was carried out in the presence of H2 or O2 as a function of temperature. In a stream of H2, metallic platinum deposited in the interlayer was found to catalytically reduce nitrate (NO3−) to N2/N2O so as to give rise to a large surface area Pt-HT nanocomposite with micro/mesoporous structure at a lower temperature of 300 °C. By contrast, the pristine HT needs to be heated at ≧400 °C to produce the porous structure. The Pt-HT composites showed the pore size distribution much narrower than the product obtained from pristine HT.