Abstract

OBESO-ESTRELLA, R. et al. Ni-mordenite system: influence of SiO₂/Al₂O₃ molar ratio on the catalytic activity in no reduction. Rev. Mex. Ing. Quím [online]. 2012, vol.11, n.3, pp.455-461. ISSN 1665-2738.

Mordenites with SiO₂/Al₂O₃molar ratio (MR) of 13, 20 and 90 were exchanged with a Ni²⁺. The samples were characterized byXRD. EDS, DRS and TEM. UV-Vis spectra of all Ni-exchanged samples were typical for a Ni(H₂O)₆²⁺ ions octahedrally coordinated by water molecules. In the UV range, samples with MR of 20 and 90 showed absorption around 250-300 nm due to partial dehydration on Ni²⁺ ions and their coordination with O^2- of the zeolite framework. It was revealed that Ni species formed on mordenite NiNaMor13 with low molar ratio are weakly? bound to the mordenite framework; as a consequence, high catalytic activity in NO reduction is observed. Easy red-on transformation of such a species rasults in the activation of propene pyrolysis with formation of carbon nanostructures.

Keywords : Ni-mordenite; SiO₂/Al₂O₃ molar ratio; carbon nanotubes; NO reduction; UV-Vis.

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