The adsorption of a methoxy radical (\(\hbox {OCH}_3\)) 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 (\(\hbox {SCH}_3\)) and methylamine (\(\hbox {NHCH}_3\)) radicals. Using dispersion-corrected DFT, we showed that the adsorption energy of \(\hbox {OCH}_3\) on gold is significantly lower than that of \(\hbox {SCH}_3\) but not very far from that of \(\hbox {NHCH}_3\). 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 \(\hbox {SCH}_3\) is very small, while that transferred to \(\hbox {NHCH}_3\) is slightly larger, but still three times smaller than in the case of \(\hbox {OCH}_3\). Concerning the competition between adsorption sites, we observed that undercoordinated atoms are not systematically more favoured than flat surfaces.

中文翻译：

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甲氧基自由基在金纳米颗粒上的吸附：与甲硫醇和甲胺自由基的比较

比较了在低能平金表面Au（111），Au（100）和Au（110）以及表面缺陷（原子）上的甲氧基自由基（\（\ hbox {OCH} _3 \））的吸附与甲硫醇（\（\ hbox {SCH} _3 \））和甲胺（\（\ hbox {NHCH} _3 \））的那些。使用色散校正的DFT，我们显示\（\ hbox {OCH} _3 \）在金上的吸附能明显低于\（\ hbox {SCH} _3 \），但与\（\ n \ hbox {NHCH} _3 \）。无论是哪种分子，我们都发现在Au（110）和Au（100）上的吸附能相同，而在Au（111）上的吸附能较小，并且电荷从表面转移到分子。费用转至\（\ hbox {SCH} _3 \）非常小，而传输到\（\ hbox {NHCH} _3 \）的则稍大，但仍比\（\ hbox {OCH} _3的情况小三倍。\）。关于吸附位点之间的竞争，我们观察到配位不足的原子没有系统地比平坦的表面更受青睐。