Real-Time Observation of Surface Bond Breaking with an X-ray Laser
2013 (English)In: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 339, no 6125, 1302-1305 p.Article in journal (Refereed) Published
We used the Linac Coherent Light Source free-electron x-ray laser to probe the electronic structure of CO molecules as their chemisorption state on Ru(0001) changes upon exciting the substrate by using a femtosecond optical laser pulse. We observed electronic structure changes that are consistent with a weakening of the CO interaction with the substrate but without notable desorption. A large fraction of the molecules (30%) was trapped in a transient precursor state that would precede desorption. We calculated the free energy of the molecule as a function of the desorption reaction coordinate using density functional theory, including van der Waals interactions. Two distinct adsorption wells-chemisorbed and precursor state separated by an entropy barrier-explain the anomalously high prefactors often observed in desorption of molecules from metals.
Place, publisher, year, edition, pages
2013. Vol. 339, no 6125, 1302-1305 p.
Research subject Chemical Physics
IdentifiersURN: urn:nbn:se:su:diva-89556DOI: 10.1126/science.1231711ISI: 000316053400033OAI: oai:DiVA.org:su-89556DiVA: diva2:619145
FunderSwedish Research Council