The high oxygen content and multiple functional groups in biomass-derived platform molecules like glucose provide a major challenge in biomass conversion to value-added fuels and chemicals. Understanding the role of multiple functionalities in the reaction on catalytically relevant surfaces, particularly with regard to deoxygenation chemistry, is paramount. In this study, temperature programmed desorption (TPD) and high resolution electron energy loss spectroscopy (HREELS) were utilized to identify the role of the multiple functionalities of glucose and model aldose glyceraldehyde in their reactions on Pt(1 1 1) and Zn modified Pt(1 1 1) surfaces. Comparisons were drawn to similar data for model molecules acetaldehyde and glycolaldehyde. For all four molecules, dehydrogenation to form an acyl intermediate, followed by decarbonylation to form CO and H-2 occurred on Pt(1 1 1). Also, with all molecules studied, addition of Zn to the Pt(1 1 1) surface caused an increase in the barrier for C-H and C-C bond scission resulting in stabilization of surface intermediates to much higher temperatures than on Pt(1 1 1). The Zn/Pt(1 1 1) surface was additionally found to be active for alcohol dissociation to form Zn-bound alkoxides, and in the case of polyols glyceraldehyde and glucose, these multiple alkoxide bonds geometrically prevented the eta(2)(C,O) aldehyde bonding configuration and subsequent carbonyl deoxygenation that was observed with smaller C-2 molecules acetaldehyde and glycolaldehyde. These results help elucidate the role of multiple alcohol functionalities in biomass-derived oxygenates in the reaction over catalytically relevant surfaces, and highlight the potential of using alloy effects (such as Zn-modification of Pt shown herein) to modify catalytic chemistry. (C) 2013 Elsevier B.V. All rights reserved.