Korean Journal of Chemical Engineering, Vol.28, No.11, 2137-2141, November, 2011
Scanning tunneling microscopy and tunneling spectroscopy studies of niobium-containing H6+xP2W18-xNbxO62 (x=0, 1, 2, 3) Wells-Dawson heteropolyacid catalysts to probe their redox property and oxidation catalysis
E-mail:
Niobium-containing H6+xP2W18-xNbxO62 (x=0, 1, 2, 3) Wells-Dawson heteropolyacids (HPAs) were investigated by scanning tunneling microscopy (STM) and tunneling spectroscopy (TS) in order to elucidate their redox properties. The HPAs formed two-dimensional well-ordered monolayer arrays on graphite surface and exhibited a distinctive current-voltage behavior called negative differential resistance (NDR) in their tunneling spectra. NDR peak voltage measured on HPA molecule was correlated with reduction potential and absorption edge energy determined by electrochemical method and UV-visible spectroscopy, respectively. NDR peak voltage of H6+xP2W18-xNbxO62 Wells-Dawson HPAs appeared at less negative voltage with increasing reduction potential and with decreasing absorption edge energy. Oxidative dehydrogenation of isobutyraldehyde was also carried out as a model reaction to probe oxidation catalysis of the HPAs. The trend of NDR peak voltage of H6+xP2W18-xNbxO62 Wells-Dawson HPAs was well consistent with the trend of yield for methacrolein.
Keywords:Heteropolyacid;Niobium;Scanning Tunneling Microscopy;Negative Differential Resistance;Redox Property
- Barth JV, Costantini G, Kern K, Nature., 437, 671 (2005)
- Tomimoto H, Sumii R, Shirota N, Yagi S, Taniguchi M, Sekitani T, Tanaka K, J. Vac. Sci. Technol. B, 18(5), 2335 (2000)
- Prauzner-Bechcicki JS, Godlewski S, Tekiel A, Cyganik P, Budzioch J, Szymonski M, J. Phys. Chem. C., 113, 9309 (2009)
- Suzuki S, Yamaguchi Y, Onishi H, Fukui K, Sasaki T, Iwasawa Y, Catal. Lett., 50(3-4), 117 (1998)
- Takimoto K, Kuroda R, Shido S, Yasuda S, Matsuda H, Eguchi K, Nakagiri T, J. Vac. Sci. Technol. B, 15(4), 1429 (1997)
- Lauritsen JV, Vang RT, Besenbacher F, Catal. Today, 111(1-2), 34 (2006)
- Matthiesen J, Wendt S, Hansen JØ, Madsen GKH, Lira E, Galliker P, Vestergaard EK, Schaub R, Laegsgaard E, Hammer B, Besenbacher F, ACS Nano., 3, 517 (2009)
- Stipe BC, Rezaei MA, Ho W, Science, 280(5370), 1732 (1998)
- Johansson MKJ, Gray SM, Johansson LSO, J. Vac. Sci. Technol. B., 14, 1015 (1998)
- Mussig HJ, Kruger D, Hinrich S, Hansson PO, Surf. Sci., 314, L884 (1994)
- Guisinger NP, Greene ME, Basu R, Baluch AS, Hersam MC, Nano Lett., 4, 55 (2004)
- Grobis M, Wachowiak A, Yamachika R, Crommie MF, Appl. Phys. Lett., 86, 204102 (2005)
- Fan Z, Chen K, Wan Q, Zou BS, Duan W, Shuai Z, Appl. Phys. Lett., 92, 263304 (2008)
- Lindsay SM, Sankey OF, Li Y, Herbst C, J. Phys. Chem., 94, 4655 (1990)
- Song IK, Kaba MS, Coulston G, Kourtakis K, Barteau MA, Chem. Mater., 8, 2352 (1996)
- Song IK, Barteau MA, Korean J. Chem. Eng., 19(4), 567 (2002)
- Mizuno N, Misono M, Chem. Rev., 98(1), 199 (1998)
- Park DR, Hong UG, Song SH, Seo JG, Baeck SH, Chung JS, Song IK, Korean J. Chem. Eng., 27(2), 465 (2010)
- Bang Y, Park DR, Lee YJ, Jung JC, Song IK, Korean J. Chem. Eng., 27, 79 (2011)
- Briand LE, Baronetti GT, Thomas HJ, Appl. Catal. A: Gen., 256(1-2), 37 (2003)
- Weber RS, J. Phys. Chem., 98(11), 2999 (1994)
- Jonnevijlle F, Tourne CM, Tourne GF, Inorg. Chem., 21, 2742 (1982)
- Park DR, Song JH, Lee SH, Song SH, Kim H, Jung JC, Song IK, Appl. Catal. A: Gen., 349(1-2), 222 (2008)
- Park DR, Choi JH, Park S, Song IK, Appl. Catal. A: Gen., 394(1-2), 201 (2011)
- Dawson B, Acta. Cryst., 6, 113 (1953)
- Yamase T, Chem. Rev., 98(1), 307 (1998)
- Youn MH, Park DR, Jung JC, Kim H, Barteau MA, Song IK, Korean J. Chem. Eng., 24(1), 51 (2007)
- Hu J, Burns RC, Guerbois JP, J. Mol. Catal. A-Chem., 152(1-2), 141 (2000)
- Misono M, Polyoxometalates: From platonic solid to anti-retroviral activity, Kluwer, Dordrecht (1994)