Two different classes of catalysts, three dolomites with different origins and two Ni-based mixed oxides containing cerium or lanthanum, were used on tar removal by steam reforming. Mixed oxides presented higher toluene conversion than dolomites, which lost activity due to hydration and carbonation. Mixed oxides were quite active for toluene steam reforming, obtaining high conversions for long periods, 16 h at 700 degrees C and 70 hat 800 degrees C. Despite the good activity, the samples showed high coke content after reaction, probably caused by the low steam/carbon ratio. The coked catalyst can be completely regenerated by steam. Thermodynamic simulation of coking tendency showed that carbon is formed at low temperatures even at high steam/carbon ratios. (C) 2017 Elsevier B.V. All rights reserved.