Preparation of size-controlled Pt catalysts supported on alumina

It was found that Pt particles on Al2O3-supported Pt catalysts prepared usi ng Pt complex nanoparticles formed in a water-in-oil microemulsion became v ery small and uniform compared to those prepared using reduced Pt metal nan oparticles or by an impregnation method. Moreover, the catalytic activity o f the catalyst composed of very small Pt particles, which was prepared usin g the complex nanoparticles, was higher in the NO-CO reaction than those of the other catalysts.