Raman spectroscopic studies on the sulfation of cerium oxide

被引:80
作者
Twu, J [1 ]
Chuang, CJ [1 ]
Chang, KI [1 ]
Yang, CH [1 ]
Chen, KH [1 ]
机构
[1] ACAD SINICA,INST ATOM & MOL SCI,TAIPEI,TAIWAN
关键词
D O I
10.1016/S0926-3373(96)00085-9
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
In the present study, we have examined sulfation of cerium oxide via impregnation of (NH4)(2)SO4, followed by heating in the temperature range of 220-720 degrees C, using Raman Spec troscopy. Based on the S-O and S=O stretching frequencies in the range of 900-1400 cm(-1), a wide range of surface oxysulfur species and bulk cerium-oxy-sulfur species are identified. At 220 degrees C, a mixture of(NH4)(2)SO4 crystals, SO4(aq2-) and HSO4(aq1-) is found to have formed on ceria's surface, whereas complete conversion of (NH4)(2)SO4 to SO4(aq2-) and HSO4(aq1-) occurs at 280 degrees C. At 350 degrees C, formation of a mixture of surface pyrosulfate S2O7(surf.02-, consisting of two S=O oscillators and a bulk type compound identified as Ce(IV)(SO4)(x)(SO3)(2-x) (0 < x < 2) have been observed. Upon introduction of moisture, the former transforms to HSO4(surf.1-), whereas the latter remains unchanged. At 400 degrees C, only the bulk type compound can be observed. At 450 degrees C, only Ce-2(SO4)(3) is generated and remains stable until 650 degrees C. Further increase in the temperature to 720 degrees C results in the formation of CeOSO4. The present study not only provides a more thorough understanding of the sulfation of cerium oxide at a molecular level, but also demonstrates that Raman spectroscopy is a highly effective technique to characterize sulfation of metal oxides. (C) 1997 Elsevier Science B.V.
引用
收藏
页码:309 / 324
页数:16
相关论文
共 47 条
[21]   CONFORMATIONALLY DEPENDENT OXYGEN ISOTOPE EFFECTS ON THE INFRARED-SPECTRA OF 2,2-DIOXO-1,3,2-DIOXATHIANES [J].
LOWE, G ;
PARRATT, MJ .
JOURNAL OF THE CHEMICAL SOCIETY-CHEMICAL COMMUNICATIONS, 1985, (16) :1073-1074
[22]  
MCARTHUR DP, 1984, OIL GAS J, P101
[23]   AN INFRARED STUDY OF SULFATED SILICA [J].
MORROW, BA ;
MCFARLANE, RA ;
LION, M ;
LAVALLEY, JC .
JOURNAL OF CATALYSIS, 1987, 107 (01) :232-239
[24]   ON THE SURFACE-ACIDITY OF SOME SULFATE-DOPED ZRO2 CATALYSTS [J].
MORTERRA, C ;
CERRATO, G ;
EMANUEL, C ;
BOLIS, V .
JOURNAL OF CATALYSIS, 1993, 142 (02) :349-367
[25]   LEWIS AND BRONSTED ACIDITY AT THE SURFACE OF SULFATE-DOPED ZRO2 CATALYSTS [J].
MORTERRA, C ;
CERRATO, G ;
BOLIS, V .
CATALYSIS TODAY, 1993, 17 (03) :505-515
[26]   BRONSTED ACIDITY OF A SUPERACID SULFATE-DOPED ZRO2 SYSTEM [J].
MORTERRA, C ;
CERRATO, G ;
PINNA, F ;
SIGNORETTO, M .
JOURNAL OF PHYSICAL CHEMISTRY, 1994, 98 (47) :12373-12381
[27]   FTIR SPECTROSCOPIC STUDY OF THIOPHENE, SO2, AND CO ADSORPTION ON CU/AL2O3 CATALYSTS [J].
PADLEY, MB ;
ROCHESTER, CH ;
HUTCHINGS, GJ ;
KING, F .
JOURNAL OF CATALYSIS, 1994, 148 (02) :438-452
[28]   PREPARATION AND RAMAN-SPECTRA OF THALLIUM(I) DISULFITE AND THALLIUM(I) SULFITE [J].
PETER, L ;
MEYER, B .
INORGANIC CHEMISTRY, 1985, 24 (19) :3071-3073
[29]   THERMOCHEMICAL SPLITTING OF SULFUR-DIOXIDE WITH CERIUM(IV) OXIDE [J].
PETERSON, EJ ;
FOLTYN, EM ;
ONSTOTT, EI .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1983, 105 (26) :7572-7573
[30]   SUPERACID PROPERTIES OF SULFATED ZIRCONIA AS MEASURED BY RAMAN AND H-1 MBS NMR-SPECTROSCOPY [J].
RIEMER, T ;
SPIELBAUER, D ;
HUNGER, M ;
MEKHEMER, GAH ;
KNOZINGER, H .
JOURNAL OF THE CHEMICAL SOCIETY-CHEMICAL COMMUNICATIONS, 1994, (10) :1181-1182