Calorimetric heats of dissociative adsorption for O-2 on Rh{100}

Using single crystal adsorption calorimetry (SCAC), the coverage dependent heats of adsorption and sticking coefficients for oxygen on Rh(100) were measured. This is the first time that SCAC experiments have been performed on a Rh crystal. In conjunction with results obtained by other techniques, it is possible to assign different regimes in the measured heat and sticking curves to different phases in the adsorption process. These are identified with the formation of particular adsorbate structures, namely the p(2 x 2) and the c(2 x 2) and (2 x 2)p4g structures, respectively. The initial heat of adsorption was found to be 386 kJ mol(-1). and the initial sticking coefficient 0.74. (C) 1998 Elsevier Science B.V. All rights reserved.