کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5423647 | 1507946 | 2011 | 7 صفحه PDF | دانلود رایگان |
Total energy calculations based on the density functional theory (DFT) with ultrasoft pseudopotential, generalized gradient spin-polarized approximation and the partial structural constraint path minimization (PSCPM) method were carried out to establish the energetically more favorable reaction pathways for the self-coupling reaction of coadsorbed CF2(ads) leading to the formation of CF2=CF2(ads) on the Cu(111) surface. In addition, the calculated electronic properties, namely partial density of states (PDOS), suggest that the initial breaking of the Cu(111)-CF2(ads) bond associating with the electron delocalization on the Cu(111) surface and the electron transfer from Cu(111) to both units of CF2(ads) are factors controlling the energy barrier for self-coupling reaction. Finally, the calculated energy barrier (0.310 eV) for the self-coupling reaction of CF2(ads) coadsorbed on the Cu(111) surface in comparison with that (0.204 eV) for the single α-fluoride elimination of adsorbed CF3(ads) on the Cu(111) surface qualitatively manifests that the formation of CF2 = CF2(g) at 250 K is limited by the self-coupling reaction of coadsorbed CF2(ads) instead of the single α-fluoride elimination of adsorbed CF3(ads).
Journal: Surface Science - Volume 605, Issues 1â2, January 2011, Pages 131-137