The effect of C-OH functionality on the surface chemistry of biomass-derived molecules: Ethanol chemistry on Rh(100)

B. Caglar, M.O. Özbek, J. W. Niemantsverdriet, C. J. Weststrate

Research output: Contribution to journalArticleAcademicpeer-review

6 Citations (Scopus)

Abstract

The adsorption and decomposition of ethanol on Rh(100) was studied as a model reaction to understand the role of C-OH functionalities in the surface chemistry of biomass-derived molecules. A combination of experimental surface science and computational techniques was used: (i) temperature programmed reaction spectroscopy (TPRS), reflection absorption infrared spectroscopy (RAIRS), work function measurements (Kelvin Probe-KP), and density functional theory (DFT). Ethanol produces ethoxy (CH3CH2O) species via O-H bond breaking upon adsorption at 100 K. Ethoxy decomposition proceeds differently depending on the surface coverage. At low coverage, the decomposition of ethoxy species occurs via β-C-H cleavage, which leads to an oxometallacycle (OMC) intermediate. Decomposition of the OMC scissions (at 180-320 K) ultimately produces CO, H2 and surface carbon. At high coverage, along with the pathway observed in the low coverage case, a second pathway occurs around 140-200 K, which produces an acetaldehyde intermediate via α-C-H cleavage. Further decomposition of acetaldehyde produces CH4, CO, H2 and surface carbon. However, even at high coverage this is a minor pathway, and methane selectivity is 10% at saturation coverage. The results suggests that biomass-derived oxygenates, which contain an alkyl group, react on the Rh(100) surface to produce synthesis gas (CO and H2), surface carbon and small hydrocarbons due to the high dehydrogenation and C-C bond scission activity of Rh(100).

Original languageEnglish
Pages (from-to)30117-30127
Number of pages11
JournalPhysical Chemistry Chemical Physics
Volume18
Issue number43
DOIs
Publication statusPublished - 21 Nov 2016

Fingerprint Dive into the research topics of 'The effect of C-OH functionality on the surface chemistry of biomass-derived molecules: Ethanol chemistry on Rh(100)'. Together they form a unique fingerprint.

  • Cite this