Reversible oxidation of ethylene on ferroelectric BaTiO3(001): An X-ray photoelectron spectroscopy study

Adsorption and desorption of ethylene on BaO-terminated (001) barium titanate are investigated by X-ray photoelectron spectroscopy. Carbon is found in an oxidized state, at a binding energy similar to that resulting from CO adsorption on BaTiO3(001). The amount of carbon adsorbed on the surface is also similar to the case of CO/BaTiO3(001). Upon heating the substrate up to the loss of its ferroelectric polarization, the C 1s signal from the oxidized spectral region vanishes. At the same time, there was no noticeable oxygen depletion of the surface after repeated C2H4 adsorption and desorption. The substrate remains stable after repeated oxidative adsorption and desorption of ethylene. Desorption occurs at different temperatures, depending on the adsorption temperature, which suggests different adsorption geometries: non-dissociated adsorption at high temperature with ethylene bond on two surface oxygen atoms, and locally dissociated adsorption at lower temperatures, in “formaldehyde-like” local configurations. [Display omitted] •Adsorption of zero dipole moment hydrocarbon molecule on an ultraclean ferroelectric.•Ethylene, when adsorbed on (001) barium titanate, gets oxidized.•Adsorbed species are desorbed by heating above the Curie temperature of the substrate.•Adsorption governed by molecular polarization due to the ferroelectric substrate.•Adsorption as ethylene bound to surface oxygen or formaldehyde configuration.•The barium titanate substrate not affected by repeated adsorption/desorption cycles.