We have previously reported Fe-Al-Cu catalysts prepared by the sol-gel method to exhibit superior water-gas shift performance compared to catalysts of similar composition prepared by precipitation/impregnation techniques. The difference in performance was ascribed to the formation of the gamma-Fe2O3 structure and a better incorporation and distribution of Cu in the iron oxide matrix. In the current study, the effect of the Cu loading level was examined for its influence on surface and structural properties, and in turn, catalytic performance. Catalysts with various Cu loading levels were evaluated at steady state at different reaction temperatures. In situ X-ray diffraction was used to monitor crystalline phases present in catalysts with different Cu loadings and phase evolution during reduction. The role of Cu loading in gamma-Fe2O3 structure formation was studied using X-ray diffraction and Mossbauer spectroscopy techniques. (C) 2009 Elsevier B.V. All rights reserved.