The searching for more practical applications of single-site heterogeneous catalysis has attracted much attention recently. Here the hydrogenation of acrolein on AuOH/m-ZrO2 is extensively investigated theoretically aiming to verify whether a desired selectivity toward allyl alcohol can be achieved. Although similar hydrogenation reactions have been reported for Au/oxides catalysts in experiment, it is not clear what the active Au component is. In this work we evaluate both the stability and the activity of single Au supported on monoclinic ZrO2 surfaces from first principles. Our calculated results indicate that Au clusters are the most stable form on the flat m-ZrO2 surface, while single Au cations can be available on the stepped m-ZrO2 sites below 350 K at ambient (oxidizing) conditions. Importantly, we demonstrate that the minority species, AuOH/M-ZrO2((2) over bar 12), exhibits the desired catalytic selectivity for the hydrogenation of acrolein. The deep hydrogenation to propyl alcohol can also be prevented kinetically on this single-site heterogeneous catalyst. (C) 2009 Elsevier Inc. All rights reserved.