TY - JOUR A1 - Ostrom, H. A1 - Oberg, H. A1 - Xin, H. A1 - Larue, J. A1 - Beye, Martin A1 - Gladh, J. A1 - Ng, M. L. A1 - Sellberg, J. A. A1 - Kaya, S. A1 - Mercurio, G. A1 - Nordlund, D. A1 - Hantschmann, Markus A1 - Hieke, F. A1 - Kuehn, D. A1 - Schlotter, W. F. A1 - Dakovski, G. L. A1 - Turner, J. J. A1 - Minitti, M. P. A1 - Mitra, A. A1 - Moeller, S. P. A1 - Föhlisch, Alexander A1 - Wolf, M. A1 - Wurth, W. A1 - Persson, Mats A1 - Norskov, J. K. A1 - Abild-Pedersen, Frank A1 - Ogasawara, Hirohito A1 - Pettersson, Lars G. M. A1 - Nilsson, A. T1 - Probing the transition state region in catalytic CO oxidation on Ru JF - Science N2 - Femtosecond x-ray laser pulses are used to probe the carbon monoxide (CO) oxidation reaction on ruthenium (Ru) initiated by an optical laser pulse. On a time scale of a few hundred femtoseconds, the optical laser pulse excites motions of CO and oxygen (O) on the surface, allowing the reactants to collide, and, with a transient close to a picosecond (ps), new electronic states appear in the OK-edge x-ray absorption spectrum. Density functional theory calculations indicate that these result from changes in the adsorption site and bond formation between CO and O with a distribution of OC-O bond lengths close to the transition state (TS). After 1 ps, 10% of the CO populate the TS region, which is consistent with predictions based on a quantum oscillator model. Y1 - 2015 U6 - https://doi.org/10.1126/science.1261747 SN - 0036-8075 SN - 1095-9203 VL - 347 IS - 6225 SP - 978 EP - 982 PB - American Assoc. for the Advancement of Science CY - Washington ER -