Catalytic activity and surface characteristics of layered Zn–Al–Si materials supported platinum

The present work aims at the preparation and characterization of novel catalysts based on layered double hydroxide structures (LDHs) containing Zn2+, Al3+ and Si4+ 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.

Research Highlights
► 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.