The adsorption and reactions of ethanol on Ru(0001) were studied with temperatureprogrammed desorption (TPD) and reflection-absorption infrared spectroscopy (RAIRS). Ethanol was found to adsorb intact onto Ru(0001) below 100 K. Heating to 250 K resulted in formation of ethoxy groups, which undergo further decarbonylation to CO, hydrogen, and surface carbon. No evidence for the formation of significant amounts of other molecules, such as methane, aldehydes, alkanes, alkenes or higher alcohols was found. This suggests that the decarbonylation takes place via beta-hydrogen abstraction, involving an oxametallacycle intermediate, similar to the previously identified decarbonylation mechanism of ethanol on Rh(111) and Co. The deposited surface carbon acts as a poison for subsequent cycles of ethanol decarbonylation, as evidenced by a decreasing CO yield in TPD and RAIRS after an increasing number of adsorption-desorption cycles. Quantification of the TPD results suggests that the reaction of a full monolayer (ML) of adsorbed ethanol results in a CO yield of about 0.1 ML in the first reaction cycle. This limited CO yield can be attributed to desorption of molecular ethanol at temperatures below 250 K. In combination with ethanol clustering upon heating, as was previously evidenced for methanol on Ru(0001) , the coverage of ethoxy groups available for decarbonylation is limited to about 0.1 ML.
|Publication status||Published - 3 Sep 2012|
|Event||29th European Conference On Surface Science, ECOSS 2012 - Edinburgh, United Kingdom|
Duration: 3 Sep 2012 → 7 Sep 2012
Conference number: 29
|Conference||29th European Conference On Surface Science, ECOSS 2012|
|Period||3/09/12 → 7/09/12|