In-situ ATR-IR study of surface reaction during aqueous phase reforming of glycerol, sorbitol and glucose over Pt/γ-Al2O3

[Display omitted] •Surface reactions during Aqueous Phase Reforming are studied by ATR IR spectroscopy.•Linearly bound and bridging CO are formed as common surface species on Pt particles.•Bridging CO can be converted by water-gas shift even at room temperature.•Co-adsorbed species affect the rate of formation and conversion of CO.•The conversion of glucose is hindered due to the formation of cyclic hemiacetals. Surface reactions involved in aqueous phase reforming of glycerol, sorbitol and glucose over Pt/γ-Al2O3 are studied by in-situ attenuated total reflection infrared (ATR-IR) spectroscopy. In these experiments aqueous solutions of the reactants are flowed over a catalyst layer that is coated on the internal reflection element of the spectroscopic cell. Linearly bound CO (COL) and bridging CO (COB) are readily formed on the Pt particles at 24–72 °C. The relative abundance of CO in different environments and the rates of formation and conversion of these species provide insight into the reaction path of different oxygenates. Even at 24 °C, COB can be converted by the water-gas shift reaction. During the conversion of sorbitol and glucose, the formation and conversion of adsorbed CO is affected by the presence of co-adsorbed reactants or by-products. In addition to CO, surface bound alkoxy species are observed during the conversion of sorbitol and glucose.