TY - JOUR
T1 - Raman Observation of the "volcano Curve" in the Formation of Carbonized Metal-Organic Frameworks
AU - Pei, Tsung
AU - Zhang, Zhao Quan
AU - Li, Bing Han
AU - Vinu, Madhan
AU - Lin, Chia Her
AU - Lee, Szetsen
N1 - Funding Information:
near the summit of the volcano. The presence of the G′ band is closely related to well-stacked carbon structures catalytically grown with metals such as Mn, Fe, Co, and Ni. In Figure 3, Fe is at the summit position of the IG′/IG curve. The physical/ chemical meaning of x-axis of the volcano curve can be multiple. It can be the atomic number in the periodic table, the number of the valence shell electrons of the metal M, or the number of the d electrons of the metal ion M2+. Additionally, please refer to the Supporting Information; we find that the volcano curve correlation is supported by the PXRD spectra of acid-treated CMOFs (Mn, Fe, Co, and Ni). The graphite (002) peak around 26° is strong, with Fe-CMOF the strongest. Again, it shows that Mn, Fe, Co, and Ni play important roles in the catalytic formation of graphitic structure.
Funding Information:
This work was supported by the Ministry of Science and Technology of Taiwan (NSC 100-2738-M-033-001-MY3, NSC 100-2632-M-033-001-MY3, MOST 103-2632-M-033-001-MY3, and MOST 103-2113-M-033-003).
Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/10/19
Y1 - 2017/10/19
N2 - The carbonization of various types of metal-organic frameworks (MOFs) was carried out under N2 gas flow and high temperature. The formation of carbonized MOFs (CMOFs) was monitored by Raman spectroscopy. In addition to the well-known D and G bands in Raman spectra, the salient G′ band feature was observed only in Mn-, Fe-, Co-, and Ni-containing CMOFs. On the other hand, CMOFs containing other metals (Al, Cr, V, Cu, and Zr) do not show the G′ band. Furthermore, the G′ band was also observed when we mixed the nitrate salts of Mn(II), Fe(III), and Co(II) with Al-containing MOFs using the same treatment conditions as in the formation of CMOFs. The G′ band is known to be related to the stacking order of graphitic layers. The presence of the Raman G′ band in CMOFs can be ascribed to the catalytic activity of Mn, Fe, Co, and Ni. The trend of the G′ band to G band intensity ratio resembles the "volcano curve" in the description of the behavior of catalytic activities of transition metals. The G′ bands in Mn-, Fe-, Co-, and Ni-containing CMOFs were well-fitted with two-component peaks which indicates that these CMOFs have well-stacked graphitic structures.
AB - The carbonization of various types of metal-organic frameworks (MOFs) was carried out under N2 gas flow and high temperature. The formation of carbonized MOFs (CMOFs) was monitored by Raman spectroscopy. In addition to the well-known D and G bands in Raman spectra, the salient G′ band feature was observed only in Mn-, Fe-, Co-, and Ni-containing CMOFs. On the other hand, CMOFs containing other metals (Al, Cr, V, Cu, and Zr) do not show the G′ band. Furthermore, the G′ band was also observed when we mixed the nitrate salts of Mn(II), Fe(III), and Co(II) with Al-containing MOFs using the same treatment conditions as in the formation of CMOFs. The G′ band is known to be related to the stacking order of graphitic layers. The presence of the Raman G′ band in CMOFs can be ascribed to the catalytic activity of Mn, Fe, Co, and Ni. The trend of the G′ band to G band intensity ratio resembles the "volcano curve" in the description of the behavior of catalytic activities of transition metals. The G′ bands in Mn-, Fe-, Co-, and Ni-containing CMOFs were well-fitted with two-component peaks which indicates that these CMOFs have well-stacked graphitic structures.
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U2 - 10.1021/acs.jpcc.7b07871
DO - 10.1021/acs.jpcc.7b07871
M3 - Article
AN - SCOPUS:85032855685
SN - 1932-7447
VL - 121
SP - 22939
EP - 22947
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 41
ER -