Catalysts With High Ni Dispersion Derived From In-Situ Synthesized LDHs On Alumina And Their Cartalytic Activity For Hydrodechlorination

Conventionally, supported metal catalysts are prepared by impregnating supports in aqueous solutions containing active metals. The properties of catalysts prepared by this method are not fully reproducible because of high surface tension of water. The most evident fact is to lead to inhomogeneity in distribution of the metal supported. Moreover, this inhomogeneity will be usually enhanced during the calcination process at high temperature.Layered double hydroxides (LDHs) are a group of anionic clays. As a result of lattice orientation effect, bivalent and trivalent metal cations are uniformly dispersed in the sheets of LDHs. This potential advantage of LDHs can be used as precursor to make metal catalysts in which active metals highly disperse. After further calcination and reduction, the highly dispersed and stable metal particles on the surface will be obtained.NiAl-CO3-LDHs/γ-Al2O3 samples prepared using an in-situ synthesis technique are used as a precursor of NiO/γ-Al2O3 catalysts. The crystalline structure, chemical composition and porous structure were characterized by means of XRD, FT-IR and N2 adsorption-desorption. NiAl-CO3-LDHs/γ-Al2O3 possesses higher specific area and narrower pore distribution, in which NiAl-CO3-LDHs are located on the surface of γ-Al2O3 and share the same Al-O bonds with the γ-Al2O3 lattice. After...