This study is a continuation of the research reported recently that showed La and V doubly promoted Rh/SiO2 catalysts to be active and selective for the synthesis of ethanol from syngas. In this work, the effect of Fe on Rh-La-V/SiO2 was examined and the role of each individual promoter was further scrutinized. Several series of promoted Rh/SiO2 catalysts were prepared by incipient wetness and characterized by BET, XRD, TEM. FTIR, TPR, and H-2-TPD. The catalytic activity was tested using a fixed-bed differential reactor at 230 degrees C and 1.8 atm. It was found that the addition of 0.8 wt% Fe, 2.6 wt% La, and 1.5 wt% V to 1.5 wt% Rh/SiO2 resulted in the highest selectivity to ethanol (34.6%) and a moderate activity compared to other promoted catalysts. The investigation based on the catalytic performance and other characterizations of Rh/SiO2. promoted by different promoters suggests that the primary promoting effects of La, V, and Fe are different. The main effects of the addition of different promoters in this study appear to be increasing CO adsorption and insertion for La, decreasing CO adsorption but enhancing CO dissociation and chain growth for V, and decreasing CO adsorption but enhancing hydrogenation for Fe. The synergistic effects of the multiple promoters indicate that the key in catalyst design for ethanol synthesis from syngas is to optimize CO dissociation, hydrogenation. and CO insertion in a balanced way. (C) 2009 Elsevier Inc. All rights reserved.