This paper presents a reactive ion exchange synthesis method of nano-CeO2 with positive cerium preexchanged ion exchange resin as precursor and ( NH4) 2CO3 as precipitant. The resultant precipitate was dried at 100 ℃ for 12 h and then was calcined at 500 K in air. The effects of ion exchange temperature and reaction time on the diameter of CeO2 particle were discussed. The TEM images show that the samples prepared with one step reactive ion exchange method are composed of nano-club with the length about 300 nm.
In this paper,a carbon based iridium (Ir) catalyst was prepared by an ion exchange procedure using H2IrCl6 as precursor and a strong basic anion exchange resin as substrate. The Ir/Carbon sample was obtained by carbonizing the precursor. Effects of carbonization parameters such as temperature and time on size and dispersion of iridium crystallite were studied. Samples were prepared at 400 oC and 500 oC to investigate the effect of carbonization temperature. The SEM image of the Ir/Carbon composite shows a hard particle of 0. 2 - 0. 4 mm in diameter,which maintains a spherical shape. The TEM images of the catalyst show that no obvious effects of carbonization temperature or time are observed on the iridium particle size. Calcinated Ir nanoparticles prepared in ion exchange still keep their small particle-sized and narrow-sized distribution. The content of Ir supported on carbon can be well controlled simply by adjusting the relative ratio of Ir to carbon. Such a promising synthesis procedure is a versatile approach that can be extended to the fabrication of some carbon-supported metal catalysts or as a simple,rapid,and highly sensitive method.
