Taguchi method, extensively applied for the optimization of multifactor processes in the most diverse fields, is for the first time applied to the synthesis of hybrids based on C nanotubes by iron-catalyzed chemical vapor deposition in 1:1 i-C4H10 + H-2 atmosphere. For this purpose, assumed synthesis-temperature (500 degrees C, 600 degrees C or 700 degrees C), support-material (alumina, magnesia or Na+-exchanged K10 montmorillonite), calcination (450 degrees C, 600 degrees C or 750 degrees C) and reduction (500 degrees C, 600 degrees C or 700 degrees C) temperature of the iron catalysts as the four factors of importance in the process, nine suitably designed experiments are conducted and the influence is evaluated of the four three-level factors on the issue of the process in terms of selectivity toward nanotubes, catalytic yield and content of carbonaceous and metallic impurities in the C nanotubes. By this procedure, the configurations giving optimal results are predicted, and tested by carrying out new experiments. (C) 2012 Elsevier Ltd. All rights reserved.