Mono- and bimetallic catalysts (An, Pt, I'd and Rh) in form of supported particles or colloidal dispersions were tested in the aerobic oxidation Of D-glucose to D-gluconic acid in water solution under mild conditions. Whereas the activity of single metals under acidic conditions was weak in the case of Au and Pt (TOF = 51-60 h(-1)) and very low in the case of Rh and Pd (TOF < 2), the activity of the bimetallic particles resulted enhanced by combining An with Pd and Pt. In the latter case high TOF's (max 924 h(-1)) allow a new route to the synthesis of gluconic acid. In the presence of alkali at pH 9.5, the oxidation of glucose to gluconate resulted remarkably improved either in the case of monometallic gold or bimetallic catalysts. but no evident synergetic effects among metals have been detected. (c) 2006 Elsevier B.V. All rights reserved.