Acidity study of Nb-containing MCM-41 mesoporous materials. Comparison with that of Al-MCM-41

被引：84

作者：

Ziolek, M ^{[1
]}

Nowak, I ^{[1
]}

Lavalley, JC ^{[1
]}

机构：

[1] UNIV CAEN, ISMRA, CNRS, URA 414, LAB CATALYSE & SPECTROCHIM, F-14050 CAEN, FRANCE

来源：

CATALYSIS LETTERS | 1997年 / 45卷 / 3-4期

关键词：

Nb-MCM-41; Al-MCM-41; hydrogen forms; acidity; FTIR; test reactions;

D O I：

10.1023/A:1019000619962

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：

The acidity of Nb-MCM-41 molecular sieves as well as their hydrogen forms was studied using FTIR spectroscopy with pyridine and 2,6-dimethylpyridine as probe molecules and in test reactions (isopropanol and cumene decomposition). The number of Lewis acid sites (LAS) and Bronsted acid sites (BAS) was estimated from the intensity of IR bands at 1450 and 1549 cm(-1) respectively. The acidity of niobium-containing materials was compared with that of Al related molecular sieves. The parent Al- and Nb-MCM-41 mesoporous materials studied in this work did not show Bronsted acidity which only appeared after ammonium exchange followed by calcination. The number and the strength of BAS was much higher on H,Al-containing material than that on H,Nb-containing molecular sieves. H,Nb-MCM-41 exhibited a higher concentration of LAS than H,Al related material.

引用

页码：259 / 265

页数：7

共 36 条

[21] STABILITY OF NIOBIUM OXIDE CATALYST ACTIVITY EMERGING IN REDUCTIVE MEDIUM [J].

MORIKAWA, A ;

TOGASHI, A .

CATALYSIS TODAY, 1993, 16 (3-4) :333-339

[22] SURFACE-PROPERTIES AND CATALYTIC ACTIVITIES OF AMORPHOUS NIOBIUM PHOSPHATE AND A COMPARISON WITH THOSE OF H3PO4-TREATED NIOBIUM OXIDE [J].

OKAZAKI, S ;

WADA, N .

CATALYSIS TODAY, 1993, 16 (3-4) :349-359

[23]

RAV PRH, 1972, J CATAL, V137, P225

[24] Synthesis of mesoporous molecular sieves: Influence of aluminum source on Al incorporation in MCM-41 [J].

Reddy, KM ;

Song, CS .

CATALYSIS LETTERS, 1996, 36 (1-2) :103-109

[25] SYNTHESIS OF MESOPOROUS VANADIUM SILICATE MOLECULAR-SIEVES [J].

REDDY, KM ;

MOUDRAKOVSKI, I ;

SAYARI, A .

JOURNAL OF THE CHEMICAL SOCIETY-CHEMICAL COMMUNICATIONS, 1994, (09) :1059-1060

[26]

SHMIDT R, 1992, J CHEM SOC CHEM COMM, P1493

[27]

Sulikowski B, 1996, HETEROGEN CHEM REV, V3, P203, DOI 10.1002/(SICI)1234-985X(199609)3:3<203::AID-HCR60>3.0.CO

[28]

2-H

[29] TITANIUM-CONTAINING MESOPOROUS MOLECULAR-SIEVES FOR CATALYTIC-OXIDATION OF AROMATIC-COMPOUNDS [J].

TANEV, PT ;

CHIBWE, M ;

PINNAVAIA, TJ .

NATURE, 1994, 368 (6469) :321-323

[30]

ULAGAPPAN N, 1996, J CHEM SOC CHEM COMM, P1047

← 1 2 3 4 →