Title : Synthesis and caracterization of CexMnY-Mg4Al2 hydrothalcite based system. application in oxidation of n-Butanol.
Abstract:
Industrial processes release a plethora of volatile organic compounds (VOCs) into the atmosphere, which adversely affect human health and contribute to air pollution, smog formation, and the degradation of urban air quality. Certain VOCs are also linked to climate change as they have the ability to trap heat in the atmosphere.. To tackle this issue, catalytic oxidation has emerged as a promising solution for the complete elimination of VOCs.
In this context, our study investigates Ce and Mn-containing MgAl LDH, focusing on its structural and catalytic properties. The MnXCeY-Mg4Al2-HT systems (with x = 0, 0.4, 0.6, and 0.8, and x+y=0.8) were prepared using a two-step calcination-reconstruction process. The effects of cerium and manganese content on the structural and catalytic properties of Ce and Mn-containing MgAl LDH were investigated. The samples underwent characterization using XRD, BET, Raman, XPS, and ATG techniques. The catalytic activity of the resulting compound in n-butanol oxidation was examined.
Increasing Ce and/or Mn contents led to changes in the structural, textural, and reducibility properties of the synthesized systems. The catalyst with high Ce content (x= 0.8 and 0.4) exhibited the highest catalytic activity, particularly for x = 0.8. Conversely, the addition of a low amount of Mn to the system (Ce0.6Mn0.2-Mg4Al2) significantly improved CO2 formation. The formation of active sites occupied by cerium and manganese within the LDH structure, contributed to the material's performance. The Ce3+/Ce4+ and Mn3+/Mn4+ redox couples in the external layers enhanced O2- diffusion and their activation into nucleophilic species, facilitating butanol transformation.
KeyWords: Catalytic oxidation, n-Butanol, Hydrotalcite, Cerium, Manganese.
