The reaction of ethanol and water has been investigated over K doped 1% Pt/Al2O3 catalysts. The presence of K resulted at room temperature in upward shift of the IR band of CO formed in the ethanol adsorption. At higher temperature the presence of surface acetate species was also detected which, according to the TPD results decomposed above 600 K to form CH4 and CO2. The K destabilized these forms. In the catalytic reaction the H-2 selectivities were similar and much higher over all promoted Pt/Al2O3 than on the pure catalyst. In this study it was proved that the K had a destabilizing effect onto the surface acetate groups and thus improved the steam reforming activity of 1% Pt/Al2O3.