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

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• 作者：Basar Caglar ; M. Olus Ozbek ; J. W. (Hans) Niemantsverdriet ; C. J. (Kees-Jan) Weststrate
• 刊名：Journal of Physical Chemistry C
• 出版年：2015
• 出版时间：October 8, 2015
• 年：2015
• 卷：119
• 期：40
• 页码：22915-22923
• 全文大小：551K
• ISSN：1932-7455

文摘

It is important to understand the interaction of C鈥揙H and C鈺怬 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鈥揙H and C鈺怬 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鈥揌 bond breaking upon adsorption at 100 K and proceeds via dehydrogenation and C鈥揅 bond breaking below room temperature, ultimately producing CO and hydrogen (synthesis gas). At high coverage a side reaction becomes apparent, involving C鈥揙 bond breaking. As a result, some methane and carbon formation are observed as well. Our findings on the decomposition of glycolaldehyde on Rh(100) suggest that sugars can be converted into synthesis gas on Rh surfaces, and, depending on the surface coverage, small hydrocarbons can be produced from sugar molecules, leaving the surface covered by surface carbon.