Bi has been employed as a modifier for AuPt/AC alloy based catalysts for the base-free glycerol oxidation. The addition of Bi has a significant effect on the selectivity of the reaction. Indeed, in the absence of Bi, the oxidation of the primary alcohol function is favored with the production of glyceric acid as main product. On the contrary, the addition of Bi promotes the oxidation of the secondary OH function leading to the production of dihydroxyacetone (DHA) as the main product (selectivity of 63% at 80% conversion). Differently from the gold-free catalyst Bi-Pt/AC, which suffers from Bi leaching, the Au modified one, namely Bi-AuPt/AC, enhances the catalyst stability by limiting the Bi leaching thus resulting in a goodselectivity to DHA even at high conversion. (C) 2014 Elsevier B.V. All rights reserved.