Issue
Korean Chemical Engineering Research,
Vol.44, No.4, 369-374, 2006
바나듐이 들어있는 Mesoporous V-AlMCM-48 분자체의 합성 및 분광학적 특성 조사
Synthesis and Spectroscopic Characterization of Vanadium-Incorporated V-AlMCM-48 Mesoporous Material
V2O5와 AlMCM-48을 고체상에서 반응시킨 후 소성하면 메조포러스 물질 내에서 V(V) 화학종이 아주 약하게 나타난다. 그러나 환원 과정을 거치면 EPR로 조사할 수 있는 바나딜 VO2+ 화학종이 생성된다. VO2+-AlMCM-48에 들어있는 바나듐의 화학적 환경을 XRD, EDX, UV-Vis, EPR, 29Si and 27Al and 51V NMR로 조사하였다. 탈수하거나 CO로 환원하면 바나듐은 MCM-48에 유사 사면체형 VO2+ 바나딜 이온 상태로 존재하며 물이 배위되면 찌그러진 팔면체 구조로 바뀐다.
A solid-state reaction of V2O5 with AlMCM-48 followed by calcination generated very weak paramagnetic VO2+ species in the mesoporous material. Dehydration and subsequent reduction with CO result in the formation of vanadyl VO2+ species that can be characterized by EPR. The chemical environment of vanadium centers in VO2+- AlMCM-48 was investigated by XRD, EDX, DR-UV-Vis, EPR, 29Si and 27Al and 51V NMR. Vanadium species in MCM-48 are existed as pseudotetrahedral VO2+ state when they were dehydrated or reduced with CO. The coordination of water on vanadyl ions transformed their structure to distorted octahedral.
[References]
  1. Prakash AM, Kevan L, J. Phys. Chem. B, 103(12), 2214, 1999
  2. Back G, Kim Y, Cho YS, Lee YI, Lee CW, J. Kor. Mag. Res. Soc., 6(1), 20, 2002
  3. Zhang WZ, Pinnavaia TJ, Catal. Lett., 38(3-4), 261, 1996
  4. Chang Z, Krishina RM, Xu J, Koodali R, Kevan L, Phys. Chem. Chem. Phys., 3, 1699, 2001
  5. Kresge CT, Leonowicz ME, Roth WJ, Vartuli JC, Beck JS, Nature, 359, 710, 1992
  6. Yoon SB, Kim JY, Yu JS, Chem. Commun., 559, 2001
  7. Xu W, Aydin M, Zakia S, Akins DL, J. Phys. Chem. B, 108(18), 5588, 2004
  8. Morey M, Davidson A, Eckert H, Stucky G, Chem. Mater., 8(2), 486, 1996
  9. Hartmann M, Racouchot S, Bichof C, Microporous Mesoporous Mater., 27, 309, 1999
  10. Luan Z, Hartmann M, Zhao D, Zhou W, Kevan L, Chem. Mater., 11(6), 1621, 1999
  11. Ryoo R, Joo SH, Kim JM, J. Phys. Chem. B, 103(35), 7435, 1999
  12. Xu J, Luan Z, Martin H, Kevan L, Chem. Mater., 11(10), 2928, 1999
  13. Xu J, Luan Z, He H, Zhou W, Kevan L, Chem. Mater., 10(11), 3690, 1998
  14. Back G, Park SG, Lee CW, J. Kor. Mag. Res. Soc., 9(2), 138, 2005
  15. Beck JS, Vartuli JC, Roth WJ, Lenowicz ME, Kresgo CT, Schmitt KD, Chu CTW, Olson DH, Sheppard EW, McCullen SB, Higgins JB, Schlenker JL, J. Am. Chem. Soc., 114(27), 10834, 1992