Angle-Resolved Measurements of Rotational and Vibrational Energies of Product CO2 in Catalytic CO Oxidation on Pd Surfaces

Abstract

Measurements of rotational and vibrational energies of desorbing products in chemical reactions provide useful information on dynamical processes of bond formation and bond rupture and also on structures of transition states. In order to obtain structural information, dependence of these energies on the desorption angle of products should be studied. However, such angle-resolved (AR) measurements of internal energies in thermal surface reactions have long time been lacking due to difficulty of experiments. Recently, measurements of internal energies of AR product CO2 in CO oxidation on Pd surfaces have become possible by detecting extremely weak infrared chemiluminescence from desorbing CO2. Rotational and vibrational energies change depending on polar and azimuth angles and also surface structures, providing new insights into structures of transition states and energy partition dynamics. In this review, recent progress in the above AR measurements is described. [DOI: 10.1380/ejssnt.2008.180]