The experimental spectrum (solid spot) with theoretical data (bars) shown and reported in Table I. Experimental solid spots are fitted by three bands corresponding to the three nonequivalent carbon species. IS stands for the initial state approximation evaluation to be distinguished from the final state approximation evaluation (FS), where core hole “ approximation” is considered. Theoretical data are referred to the most stable conformer of the gas phase alaninol whose structure is illustrated in the inset. The first band from left is associated with the methyl carbon , the second one to the , and the third to the C–OH (in IS theoretical data by Catone et al., the last two are inverted, as shown in Table I). (a) IS of Catone et al. employs the VWN exchange-correlation potential with the same basis set as the initial state and by Catone et al. adds the energy differences between the neutral molecule and the system with the core hole at the given atomic site (details in Ref. 12). (b) IS of the art evaluation with DFT and MP2 level of theory is also presented (Ref. 9). For “DFT FS,” a fixed shift of was subtracted from the VASP ionization energy to align the data with the spectrum.
Optimized geometries and energies of adsorption for the intact alaninol adsorption on Cu(100), the four most stable geometries are shown. In the first panel, OH and are grafting the surface on the top of copper atoms, and in the second panel, OH is bridge and less stable at . The third and fourth panels show the single and OH graftings respectively, the mode is the less favored.
Optimized geometries and energies of reaction obtained for radical alaninol on Cu(100), O, grafting and O grafting are shown. O, grafting reaction energy indicates this form to be the most favored on the surface. Bond lengths are decreased, , due to the dehydrogenation reaction.
Electronic core energy levels of alaninol in vacuum in its most stable conformer. Relative energies can be compared to the experimental data and other theoretical approaches as discussed in the text.
Optimized geometries obtained for alaninol on Cu(100). We report adsorption/reaction energies (in eV) with the O–Cu and N–Cu bond lengths (in Å) for all the studied orientations of the intact and dehydrogenated alaninol on the surface; binding modes are explained in the third column. The lowest adsorption energy is found when alaninol is bonded by both O and ; we have also explored other possibilities as discussed in the text. No experimental data of the adsorption/reaction data are available.
Relative core electron level energies calculated for alaninol on Cu(100) for C ( and are referred to ), for O (referred to O of ), and N (referred to N of ). Results show that, considering an internal reference, binding energy difference of the (O, ) and (O) chemisorption structures is the closest one to the experimental values of the low coverage, in particular, for O and N . The overall resolution of the experiment is (Ref. 10).
Article metrics loading...
Full text loading...