Mg-Al (2:1) layered double hydroxides (LDH) were supported onto multi-walled carbon nanotubes (MWNTs), in order to optimize the catalytic performance of these solid base catalysts. The resulting LDH/MWNT hybrids after activation (heat-treatment/hydration) were compared to the pure activated LDH catalyst for the self-condensation of acetone. Smaller LDH crystallite sizes and a good dispersion of the LDH particles on the MWNTs increase the number of active centers accessible to acetone, and hence enhance activity. However, debris created during MWNT oxidation inhibits the reaction, leading to an optimum intermediate hybrid composition. (C) 2014 Elsevier B.V. All rights reserved.