In the present paper steam reforming of methane, ethane and ethylene was compared on Pt, Rh and Pd supported on yttrium-stabilized zirconia (YSZ). Both reactivity and product distribution changed with the use of different catalysts. The order of activity for the hydrocarbons on Rh was C2H6 > C2H4 > CH4. On Pt, methane reacted faster than the C2-hydrocarbons: CH4 > C2H6, C2H4. The lowest coking tendency was observed on Pt/YSZ. Pd/YSZ showed a high tendency to coke formation and blocked the reactor. Pt/YSZ produced synthesis gas (CO and H,) only for all hydrocarbons. However, more importantly, in this study all significant reactions during ethane steam reformine on Rh/YSZ have been clarified. Methane formation in addition to synthesis gas production on this catalyst was assigned to hydrogenolysis of ethane by consecutive conversion of hydrogen produced in ethane steam reforming. (c) 2007 Elsevier B.V. All rights reserved.