Hydrogen production from acetone steam reforming was studied using bimetallic PtNi catalysts supported on modified alumina. La-, Ce- and Mg-oxides were used as support modifiers in order to neutralize acidity and/or to improve water adsorption and OH− surface mobility of Al2O3 support. Characterization of the sample showed that metal-support interactions and the size of metallic Ni at surface differ depending on the oxide added to the alumina support. Reforming activity on Ni and Pt–Ni supported on X-modified-Al2O3 catalysts (X = La, Ce, or Mg) showed that both metal and support, play an essential role in the catalytic behavior on the steam reforming of acetone. The sequence of gasification capacity over monometallic samples (Ni/LaAl > Ni/MgAl > Ni/CeAl) points out that acidity of supports participates in the acetone reforming mechanism over these catalysts. Addition of Pt to monometallic Ni catalysts only has a beneficial effect on the reforming capacity of the Ni/LaAl sample. Improvement in the reforming capacity of the PtNi/LaAl catalyst is believed to be a consequence of the promoting effect of Pt that leads to an increase in the stability of metallic Ni particles on catalyst surface together with the ability of Pt to enhance the mobility of the H-atoms formed in the reaction could help the gasification of carbon precursors formed during the reforming of acetone.