Determination of the Rh–C bond energy for C2H2 and C2H4 reactive adsorption on Rh{100}

Coverage dependent heats of adsorption and sticking probabilities for ethylene and acetylene on Rh{100} have been measured. For C2H2 and C2H4, the initial heats of adsorption are 210±10 and 175±10 kJ mol−1, and the initial sticking probabilities are 0.86±0.01 and 0.88±0.01, respectively. No literature is available on the adsorption of acetylene on Rh{100}. However, it is known that ethylene adsorption on Rh{100} at 300 K produces σ-bonded CCH, and the corresponding Rh–C bond energy is therefore estimated as ∼268 kJ mol−1. This is used to determine the species most likely to be formed upon acetylene adsorption.