Adsorption and decoposition of ethanol on Cu2O(111) and (100)

• Ethanol dehydrogenation on metal oxides such as Cu2O is an important reaction for the production of renewable energy by fuel cells both via the production of H2 fuel and applied in direct alcohol fuel cells. To better understand this reaction we studied the adsorption, dissociation and desorption of ethanol on Cu2O(111) and (100) surfaces using high-resolution photoelectron spectroscopy (PES), vibrational sum frequency generation spectroscopy (SFG), and temperature programmed desorption (TPD) accompanied by density functional theory (DFT) calculations. On Cu2O(100) the first layer consists primarily of dissociatively adsorbed ethoxy. Second and third layers of ethanol physisorb at low temperature and desorb below 200 K. On the Cu2O(111) surface, adsorption is mixed as ethoxy, ethanol and the products following C-C cleavage, CHx and OCHx, are found in the first layer. Upon heating, products following both C-C and C-O bond breaking are observed on both surfaces and continued heating accentuates the molecular cracking. C-O cleavage occurs more on the (100) surface, whereas on the Cu2O(111) C-C cleavage dominates and occurs at lower temperatures than on the (100) surface. The increased ability of Cu2O(111) to crack ethanol is explained by the varied surface structure including both surface oxygen, electron rich O-vacancies and Cu.

Ämnesord

NATURVETENSKAP  -- Fysik -- Atom- och molekylfysik och optik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Atom and Molecular Physics and Optics (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Materialteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering (hsv//eng)

Nyckelord

kemisk fysik

Chemical Physics

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