Synthesis, Structural Analysis And Performance Of Copper-containing Hydrotalcite-like Materials

This thesis relates to a systemic study on the preparation of Cu- and Ni-containing hydrotalcite-like materials, and the relationship between the composition, the structure and the property of the products thereby obtained. A preliminary investigation has also been carried out on the relationship between the parameters of operation in the nucleation process and the particle size of the products obtained.Cu-Ni-Al-CO3 layered double hydroxides with different molar ratios of Cu2+/Ni2+ have been synthesized with separate nucleation and aging steps. The materials obtained have been characterized by XRD, FT-IR, TG-DTA, ICP and laser particle size analyzer. The influence of different molar ratios of copper and nickel ions on the crystal structure and host-guest interactions in the Cu-Ni-Al-CO3 layered double hydroxides has been investigated. Jahn-Teller effect has a strong effect on crystal structure, thermal stability and host-guest interactions because of the presence of Cu2+ ion. In addition, compared with the conventional coprecipitation method, Cu-Ni-Al-CO3 layered double hydroxides with the better crystal structure, smaller crystallites and a very narrow distribution of crystallite size can be obtained using the new method.Cu-Ni-Mg-Al-CO3 layered double hydroxides materials containing different ratios of Ni2+, Cu2+ and Mg2+ have been synthesized for the first time with separate nucleation and aging steps. The materials obtained have been characterized by XRD, FT-IR, TG-DTA, and ICP. The influence of different molar ratios of divalent metal ions on the crystal structure, selectivity of crystal growth in different directions and host-guest interactions in the Cu-Ni-Mg-Al-CO3 layered double hydroxides materials has been investigated. It was shown that Cu-Ni-Mg-Al-CO3 layered double hydroxides nanomaterials could be obtained using this method, and the influence of the Jahn-Teller effect on the crystal structure, thermal stability and host-guest interactions because of the presence of Cu2+ was quite marked. Furthermore with increasing amounts of Mg2+, the thermal stabilities of Cu-Ni-Mg-Al-CO3 layered double hydroxides materials became better.The influence of the parameters of operations such as gap size, rotational speed, slip viscosity, and concentration of reaction solutions on the particle size has been investigated primally. Laser particle size analyzer has measured the materials obtained. It was shown that the influence on the particle size was not obvious. The advantage of the method with separate nucleation and aging steps is to obtain the products with a narrow crystallite size distribution. The key step of the method to control the particle size is in the aging step.