Berlin 2015 – scientific programme
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O: Fachverband Oberflächenphysik
O 39: Heterogeneous Catalysis
O 39.5: Poster
Tuesday, March 17, 2015, 18:15–21:00, Poster A
Methanol Adsorption and Reaction on SmOx/Pt(111) Systems Studied by TPD and IRRAS — •jin-hao jhang1, andreas schaefer1, jason f. weaver2, and marcus bäumer1 — 1Institute of Applied and Physical Chemistry, Center for Environmental Research and Sustainable Technology, University of Bremen, Germany — 2Department of Chemical Engineering, University of Florida, USA
Samaria (SmOx) as one of rare earth oxides has been considered as a promising oxide catalyst as it shows, for instance, high selectivity in the oxidative coupling of methane (OCM). Whereas other rare earth oxides such as ceria have been studied intensively, detailed investigations of the surface chemistry of SmOx are still lacking. Here we used methanol (MeOH) as a smart probe molecule by means of temperature programmed desorption (TPD) and infrared reflection-absorption spectroscopy (IRRAS) to study the surface chemistry of SmOx thin films which were grown on a Pt(111) substrate. TPD results show that CO and H2 are main products of the MeOH reaction on SmOx/Pt(111). Moreover, a cooperative effect by SmOx and the Pt substrate is only observed on the non-fully covered SmOx/Pt(111). Surprisingly CO2 as an unexpected product is also found, and a measurable amount of hydrogen is missing. IRRAS results confirm the existence of methoxy and formate species during MeOH decomposition on SmOx/Pt(111) which indicates the domination of the dehydrogenation process. Additionally, monitoring the shift of the C-O stretch frequency provides information about the adsorption sites of methoxy on SmOx surfaces.