Ni-on-dolomite catalysts were found to be effective catalysts for coking resistance and promising sulfur tolerance for steam reforming of tar. Experiments were carried out in a fixed bed reactor at 730-850 degrees C with a short contact time (W/F 0.55 g h/mol) and under atmospheric pressure. Toluene and naphthalene were selected as the model component of tar. The process variables such as calcination temperature, reaction temperature and the content of nickel had substantial influence on promising sulfur tolerance in catalytic tar removal by Ni/Dolomite catalysts. Results were compared with the Ni/Al2O3, Ni/SiO2 as a representative of commercial catalysts. The novel 15%Ni/Dolomite almost gasified tar component even at 770 degrees C and the presence of 100 ppm H2S in the feed. The poisoning effect of H2S was discovered to be reversible. The suppression of the catalytic activity by adding H2S was much lower for Ni/Dolomite than Ni/Al2O3. The TGA-DTA analysis of used catalysts revealed that Ni/Dolomite exhibited high resistance to coke deposition over those of the Ni/Al2O3, Ni/SiO2, (c) 2006 Elsevier Ltd. All rights reserved.