In this study, we reported a remarkably improved catalytic activity of Mn/gamma-Al2O3 catalyst promoted with potassium doping in the selective oxidation of benzyl alcohol with molecular oxygen. Characterizations of powder X-ray diffraction (XRD), Raman spectroscopy, X-ray absorption fine structure (XAFS), and hydrogen temperature-programmed reduction (H-2-TPR) revealed that the co-impregnation of potassium to the Mn/gamma-Al2O3 gave rise to the presence of alpha-MnO2 rather than beta-MnO2, resulting in a stable catalyst with enhanced catalytic performance. We also demonstrated this alumina-supported K-Mn mixed oxide catalyst can effectively catalyze aerobic oxidation of various aromatic alcohols. (C) 2009 Elsevier B.V. All rights reserved.