Mixed oxides obtained from Layered Double Hydroxides (LDH) precursors exhibit basic properties giving rise to very efficient catalysts for syntheses of fine chemicals. Until now their properties have been mainly tailored through the activation temperature and the composition of the LDH. Alkaline, alkaline-earth or La³⁺ cations, particularly interesting to reach high basic levels, cannot be introduced in the brucite-like layers of LDHs. This work presents an original approach to avoid this drawback going through the nanocomposite route. Nanocomposites precursors have been prepared by intercalation of host Mg/Al LDH with negatively charged guest colloids. These latter are obtained by complexation of La³⁺ with strong complexing agents (citrate, edta). The intercalation degree, the composition of the colloids and the activation temperature allow to finely tune the basic properties of the mixed oxides catalysts. This has been put into evidence by physico-chemical characterizations and the reaction test of methylbutynol (MBOH) conversion. A correlation is found between the strength of the basic sites measured by microcalorimetric adsorption of CO₂ and the average charge on the oxygens calculated from Sanderson’s theory of electronegativity. The basic character of the catalysts is confirmed by the catalytic conversion of MBOH, leading to acetone and acetylene. The performances of the catalysts obtained from the nanocomposite precursors, higher than those obtained with the mixture of Mg(Al)O and lanthanum oxide, resulting from the decomposition of coprecipitated Mg/Al/La LDHs, show that a synergy between the different cations is achieved using the new nanocomposite precursors. 

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/15497 must be provided.