Abstract
The present work aims at the preparation and characterization of novel catalysts based on layered double hydroxide structures (LDHs) containing Zn
2+, Al
3+ and Si
4+ cations in host layers and platinum species supported over the surface of these structures. LDHs with different Zn/Al/Si ratios were prepared via a co-precipitation method. Characterization of Zn–Al–Si layered double hydroxides was carried out using energy-dispersive X-ray spectrometry, X-ray powder diffraction, infrared spectra, thermal analyses and scanning electron microscopy. Experimental results revealed the presence of only crystalline phases of layered double hydroxides containing about 20–40 mol% of aluminum and silicon. These novel materials are commonly used as supports for platinum catalysts. Layered double hydroxide supported platinum samples were characterized through nitrogen adsorption–desorption, X-ray powder diffraction, infrared spectra and thermal analyses. The activity of the prepared platinum catalysts was tested through cyclohexane dehydrogenation and n-hexane cracking using a pulse flow system. Our results suggested that the Zn–Al–Si layered double hydroxides have a positive catalytic effect towards dehydrogenation.
► Synthesis of a series of Zn -Al -Si new nano-layered materials. ► Zn -Al -Si LDH supported platinum has positive effect toward dehydrogenation reaction. ► The activity and selectivity of Pt/LDH are higher than that of Pt/no-LDH. ► The active role of Zn -Al -Si LDHs disappears in case of cracking reactions.