Desorption of H2O from flat and stepped Pt(111)

Picolin A, Busse C, Redinger A, Morgenstern M, Michely T

Research article (journal)

Abstract

To investigate the effect of steps on H2O binding on a nominal Pt(111) surface, we used thermal desorption spectroscopy of water adsorbed on purposefully nanostructured surfaces: a rippled surface containing densely packed (100)-microfaceted and (111)-microfaceted steps was created using grazing incidence ion bombardment, and a surface with triangular mounds mainly consisting of (111)-microfaceted steps was fabricated through homoepitaxial growth. These morphologies are determined by scanning tunneling microscopy. We find two additional high-temperature H2O desorption peaks using the rippled surface, whereas only the peak with the highest desorption temperature is present on the (111)-microfaceted mound. Thus, water preferentially binds to steps and especially favors (111)-microfaceted ones. Furthermore, the large step concentration on our nanostructured surfaces precludes the coexistence of a condensed and a diluted phase in a monolayer of water and suppresses the formation of crystalline ice multilayers during heating.

Details zur Publikation

Release year: 2009
Language in which the publication is written: English
Link to the full text: http://www.scopus.com/inward/record.url?eid=2-s2.0-65249095508&partnerID=40&md5=b88c8bd6156bab9b6f89e7dff3d01953