Methoxy radical adsorption on gold nanoparticles: a comparison with methanethiol and methylamine radicals
Résumé
The adsorption of a methoxy radical (OCH3) on the low-energy flat gold surfaces Au(111), Au(100) and Au(110) and on surface defects (adatoms) was compared with those of methanethiol (SCH3) and methylamine (NHCH3) radicals. Using dispersion-corrected DFT, we showed that the adsorption energy of OCH3 on gold is significantly lower than that of SCH3 but not very far from that of NHCH3. Whatever the molecule, we found that the adsorption energy is of the same order on Au(110) and Au(100), and smaller on Au(111) and that the charge transfer goes from the surface to the molecule. The charge transferred to SCH3 is very small, while that transferred to NHCH3 is slightly larger, but still three times smaller than in the case of OCH3. Concerning the competition between adsorption sites, we observed that undercoordinated atoms are not systematically more favoured than flat surfaces.
Domaines
Chimie-Physique [physics.chem-ph]
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