A series of Au/ZrO2 catalysts with low content of gold (<1 wt.%) were prepared by deposition-precipitation method and evaluated in the low-temperature water-gas shift reaction (WGSR) under H-2-rich reformate atmosphere. The effect of pre-calcination temperature of ZrO2 on the structural and surface properties of the freshly reduced Au/ZrO2 catalysts was investigated by XRD, N-2-physisorption, HRTEM, UV-Vis DRS, AAS, EPR and XPS characterizations. The catalytic evaluation results reveal that the one supported on ZrO2 calcined at 350 degrees C shows the best catalytic performance. Correlating to the characterization results, it is found that the catalytic performance of Au/ZrO2 catalysts strongly depends on the concentration of F-center defects on ZrO2 surface. EPR and XPS results disclose that electrons can be transferred from F-center to the supported Au, resulting in the formation of activated electron-rich Au cluster, which is responsible for the high catalytic activity of the Au/ZrO2 catalysts. moreover, the electron transfer leads to the firm anchoring of Au cluster by the F-center, thus favoring a high catalytic stability. It is proposed that the active site for WGSR on the Au/ZrO2 catalysts can be expressed as Au delta-[V-omicron(-)]Zr3+, where [V-omicron(-)] represents an F-center. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.