Manganese Oxide Octahedral Molecular Sieves (OMS-2) Multiple Framework Substitutions: A New Route to OMS-2 Particle Size and Morphology Control

被引:166
作者
King'ondu, Cecil K. [1 ]
Opembe, Naftali [1 ]
Chen, Chun-hu [1 ]
Ngala, Katana [1 ]
Huang, Hui [1 ]
Iyer, Aparna [1 ]
Garces, Hector F. [2 ]
Suib, Steven L. [1 ,2 ]
机构
[1] Univ Connecticut, Dept Chem, Storrs, CT 06269 USA
[2] Univ Connecticut, Inst Mat Sci, Storrs, CT 06269 USA
关键词
EFFECTIVE IONIC-RADII; LARGE-SCALE; CRYPTOMELANE; OXIDATION; HOLLANDITE; ALPHA-MNO2; MECHANISM; DIOXIDE; NANOMATERIALS; SPECTROSCOPY;
D O I
10.1002/adfm.201001020
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
Self-assembled multidoped cryptomelane hollow microspheres with ultrafine particles in the size range of 4-6 nm, and with a very high surface area of 380 m(2) g(-1) have been synthesized. The particle size, morphology, and the surface area of these materials are readily controlled via multiple framework substitutions. The X-ray diffraction and transmission electron microscopy (TEM) results indicate that the as-synthesized multidoped OMS-2 materials are pristine and crystalline, with no segregated metal oxide impurities. These results are corroborated by infrared (IR) and Raman spectroscopy data, which show no segregated amorphous and/or crystalline metal impurities. The field-emission scanning electron microscopy (FESEM) studies confirm the homogeneous morphology consisting of microspheres that are hollow and constructed by the self-assembly of pseudo-flakes, whereas energy-dispersive X-ray (EDX) analyses imply that all four metal cations are incorporated into the OMS-2 structure. On the other hand, thermogravimetric analyses (TGA) and differential scanning calorimetry (DSC) demonstrate that the as-synthesized multidoped OMS-2 hollow microspheres are more thermally unstable than their single-doped and undoped counterparts. However, the in-situ XRD studies show that the cryptomelane phase of the multidoped OMS-2 hollow microspheres is stable up to about 450 degrees C in air. The catalytic activity of these microspheres towards the oxidation of diphenylmethanol is excellent compared to that of undoped OMS-2 materials.
引用
收藏
页码:312 / 323
页数:12
相关论文
共 51 条
[1]   Reactivity of Nanostructured MnO2 in Alkaline Medium Studied with a Micro-Cavity Electrode: Effect of Synthesizing Temperature [J].
Benhaddad, L. ;
Makhloufi, L. ;
Messaoudi, B. ;
Rahmouni, K. ;
Takenouti, H. .
ACS APPLIED MATERIALS & INTERFACES, 2009, 1 (02) :424-432
[2]   Framework doping of iron in tunnel structure cryptomelane [J].
Cai, J ;
Liu, J ;
Willis, WS ;
Suib, SL .
CHEMISTRY OF MATERIALS, 2001, 13 (07) :2413-2422
[3]   Synthesis, Characterization, and Rietveld Refinement of Tungsten-Framework-Doped Porous Manganese Oxide (K-OMS-2) Material [J].
Calvert, Craig ;
Joesten, Raymond ;
Ngala, Katana ;
Villegas, Josanlet ;
Morey, Aimee ;
Shen, Xiongfei ;
Suib, Steven L. .
CHEMISTRY OF MATERIALS, 2008, 20 (20) :6382-6388
[4]   Large-scale synthesis of CuO shuttle-like crystals via a convenient hydrothermal decomposition route [J].
Chen, D ;
Shen, GZ ;
Tang, KB ;
Qian, YT .
JOURNAL OF CRYSTAL GROWTH, 2003, 254 (1-2) :225-228
[5]   Characterization of manganese oxide octahedral molecular sieve (M-OMS-2) materials with different metal cation dopants [J].
Chen, X ;
Shen, YF ;
Suib, SL ;
O'Young, CL .
CHEMISTRY OF MATERIALS, 2002, 14 (02) :940-948
[6]   Nonaqueous sol-gel syntheses of microporous manganese oxides [J].
Ching, S ;
Welch, EJ ;
Hughes, SM ;
Bahadoor, ABF ;
Suib, SL .
CHEMISTRY OF MATERIALS, 2002, 14 (03) :1292-1299
[7]   Sol-gel route to the tunneled manganese oxide cryptomelane [J].
Ching, S ;
Roark, JL ;
Duan, N ;
Suib, SL .
CHEMISTRY OF MATERIALS, 1997, 9 (03) :750-754
[8]   Synthesis of a new hollandite-type manganese oxide with framework and interstitial Cr(III) [J].
Ching, S ;
Driscoll, PF ;
Kieltyka, KS ;
Marvel, MR ;
Suib, SL .
CHEMICAL COMMUNICATIONS, 2001, (23) :2486-2487
[9]   Hierarchically mesostructured doped CeO2 with potential for solar-cell use [J].
Corma, A ;
Atienzar, P ;
García, H ;
Chane-Ching, JY .
NATURE MATERIALS, 2004, 3 (06) :394-397
[10]  
*CRYSTALMAKER SOFT, 1994, CRYSTALMAKER CRYST M