Hydrogen isotope exchange in a coverage obtained on Ir(111) by ethylene adsorption

HREELS and SIMS studies of hydrogen isotopc exchange in a coverage obtained on Ir(111) by ethylene adsorption are carried out at 180–450 K and at a hydrogen (deuterium) pressure up to 8×10⁶ Pa. The ethylidyne species have shown a high stability towards hydration and structural changes upon hydrogen (deuterium) exposures. Under these conditions hydrogen exchange in the methyl groups is a slow process. With increasing temperature the hydrogen exchange in the decomposition products of ethylidyne (C₂H species) is quick and depends on the exchanged amount of atomically adsorbed hydrogen.