Modeling the Surface Chemistry of Sugars: Glycolaldehyde on Rhodium (100)

Abstract

It is important to understand the interaction of C–OH and C═O functional groups of sugar with a catalytically active metal surface for selectively converting of biomass-derived molecules into useful chemicals. Glycolaldehyde (HOCH2CHO), with its C–OH and C═O functional groups, is the smallest molecule to model aspects of the chemistry of sugars on metal surfaces. Rhodium catalysts are candidates for activation of biomass-derived molecules. We have investigated the decomposition of glycolaldehyde on the Rh(100) surface using a combination of experimental surface science techniques (temperature-programmed reaction spectroscopy (TPRS), reflection absorption infrared spectroscopy (RAIRS)) and a computational method (density functional theory (DFT)). At low coverage, glycolaldehyde decomposition commences with O–H bond breaking upon adsorption at 100 K and proceeds via dehydrogenation and C–C bond breaking below room temperature, ultimately producing CO and hydrogen (synthesis gas). At high coverage a side rea...