精品干货：SCI论文中如何描述XAS的实验结果？

1. 如何非常详细地描述 XAS 实验结果？

实例：To further verify the structural differences between PdIn and Pd3In IMNCs, we used X-ray absorption spectroscopy (XAS) techniques to evaluate the electronic structure and the chemical bonding of Pd–In IMNCs in their local environment. X-ray absorption near-edge structure (XANES) of Pd K-edge for Pd–In IMNCs with reference samples Pd foil and Pd nanoparticles (NPs) is shown in Figure 5a. The monometallic Pd NPs show spectral features that are similar to that of bulk Pd foil. For Pd3In and PdIn IMNCs, the energy of adsorption edge (E0) and the height of the white line (Hw) are lower than those of Pd foil and Pd NPs, which suggests the electron-richness of Pd atoms in Pd3In and PZdIn IMNCs compared to those in Pd foil and Pd NPs. This result is likely due to the electron transfer from In atoms to Pd atoms, which is consistent with the electronegativities of In (1.78) and Pd (2.20), as well as the DFT results (Table S6). Figure 5b shows the normalized In K-edge XANES spectra of Pd–In IMNCs as well as the reference sample (In powder). In comparison with In powder, PdIn IMNCs exhibit both higher E0 and Hw. This result reveals the electron deficiency at the In atoms in Pd–In IMNCs, which can be confirmed from the result of Pd K-edge XANES spectra. In Figure 5c, extended X-ray absorption fine structure (EXAFS) oscillations of Pd–In IMNCs are quite different from those of Pd foil and Pd NPs, with shorter periods and smaller amplitudes. From literature, the shorter periods are due to the longer Pd–In(Pd) distances of Pd–In IMNCs than that of monometal Pd. Smaller amplitudes indicate the low coordinate environment of Pd atoms in Pd–In IMNCs. For Pd NPs, EXAFS oscillations in K space at each absorption edge are similar and closely resemble that of Pd foil, but with smaller amplitude, which can be attributed to the finite size effect of NPs. In Figure 5d, the slight shift of the first nearest-coordination peaks in R space of PdIn and Pd3In also indicates the mild change of atomic distance. The curve fitting results of all four samples are listed in Table 2, which demonstrates that the specific Pd–In(Pd) bond length increases from 2.74 ± 0.02 Å (Pd foil and Pd NPs) to 2.77 ± 0.03 Å (PdIn) and 2.78 ± 0.03 Å (Pd3In), and the Pd–Pd bonds are absent in PdIn IMNCs. （参考文献：Li, Y. et al. J. Am. Chem. Soc., 2017, 139, 7294–7301）

▲ J. Am. Chem. Soc., 2017, 139, 7294–7301

提炼语言模板：

A. 为什么要做这个表征：To further verify the structural differences between___and ___, we used X-ray absorption spectroscopy (XAS) techniques to evaluate the electronic structure and the chemical bonding of ___in their local environment. 

变式1：To verify further that sample A contained only atomically dispersed individual __ atoms throughout the whole catalyst, extended X-ray absorption fine structure (EXAFS) spectra were measured on freshly reduced catalysts.(参考文献：Zhang, T. et al. Nature Chemistry 2011, 3, 634–641)

变式2：To evaluate the change of oxidation states of metal elements during OER, we performed XAS on the ____and ____samples before and after OER. （参考文献：Science 2016，352,333-337）

变式3：The single-atom and 2D raft structures of Pt were further characterized with extended XAFS (EXAFS) spectroscopy.（参考文献: Zhang, T. et al. Nature Commun. 2014, 5, 5634）

变式4：Element-selective XAFS spectroscopy, including EXAFS and XANES, is powerful for determining the coordination environment and chemical state of the absorbing centre with high sensitivity.(参考文献: Nature Catalysis 2018, 1, 63–72)

B. 对比样品是什么：X-ray absorption near-edge structure (XANES) of 元素 K-edge for Pd–In IMNCs with reference samples Pd foil and Pd nanoparticles (NPs) is shown in Figure 5a. 

Figure 5b shows the normalized In K-edge XANES spectra of Pd–In IMNCs as well as the reference sample (In powder).

变式：Figure 3a shows the XANES spectra for ____ samples after oxidation, reduction and re-oxidation, together with the XANES spectra of PdO and a Pd foil as reference materials. (参考文献: Nature 2002, 418, 164–167 )

C. 得到了哪些信息，说明了哪些问题:

1) The monometallic ____ NPs show spectral features that are similar to that of ___. 

变式：The edge position of the reduced sample is identical to that of the __ foil, suggesting that __ is in a metallic state.(参考文献: Nature 2002, 418, 164–167)

2) For ____, the energy of adsorption edge (E0) and the height of the white line (Hw) are lower than those of ____, which suggests the electron-richness of ___ atoms in ____compared to those in ____.

变式1：In comparison with ___, ____ exhibit both higher E0 and Hw. This result reveals the electron deficiency at the __atoms in____, which can be confirmed from the result of __ K-edge XANES spectra. 

变式2：The white-line intensity, reflecting the oxidation state of the __ species, increased steadily with a decrease of the __ loading, suggesting that the __ became more positively charged with lower __ loading. （参考文献: Zhang, T. et al. Nature Commun. 2014, 5, 5634）

变式3：Compared to the ___ spectrum, the two oxidized samples show a chemical shift of about __ eV, indicating that the valence of the __ in these materials is higher than the normal bivalence seen in ___. (参考文献: Nature 2002, 418, 164–167)

3) This result is likely due to the electron transfer from __ atoms to __ atoms, which is consistent with the electronegativities of __  and __, as well as the DFT results.

变式：In other words, lower __ loading results in higher percentage of single-atom and pseudo-single-atom structures in the catalyst, and more electron transfers from __ to the ____support. （参考文献: Zhang, T. et al. Nature Commun. 2014, 5, 5634）

4) In Figure __, extended X-ray absorption fine structure (EXAFS) oscillations of ____ are quite different from those of ____, with shorter periods and smaller amplitudes. From literature, the shorter periods are due to the longer____ distances of ___ than that of monometal ___. Smaller amplitudes indicate the low coordinate environment of ___ atoms in ____. 

变式：For __ NPs, EXAFS oscillations in K space at each absorption edge are similar and closely resemble that of ___, but with smaller amplitude, which can be attributed to the finite size effect of NPs. In ___, the slight shift of the first nearest-coordination peaks in R space of ____ also indicates the mild change of atomic distance. 

5）The curve fitting results of all four samples are listed in Table 2, which demonstrates that the specific Pd–In(Pd) bond length increases from 2.74 ± 0.02 Å (Pd foil and Pd NPs) to 2.77 ± 0.03 Å (PdIn) and 2.78 ± 0.03 Å (Pd3In), and the Pd–Pd bonds are absent in PdIn IMNCs. 

变式1：The much longer distance of ___ coordination than that in____ alloy (__ Å) suggests that __ does not directly coordinate with __; instead, according to our previous model it coordinates with __ via bridging oxygen. The relatively higher coordination number of __  also supports this conclusion.（参考文献: Zhang, T. et al. Nature Commun. 2014, 5, 5634）

变式2：____ exhibits a major peak at ___ Å, which is much shorter than the___ peak at ___ Å for the ___in ___ reference and thus can be attributed to the backscattering between ___ and light atoms. In addition, the FT of ____ also reveals a minor signal at ___ Å, which overlaps partially with the ___ peak at ___ Å for ____. (参考文献: Nature Catalysis 2018, 1, 63–72)