Determination of the electronic state and concentration of nickel in NiSAPO catalysts by magnetic measurements

被引：8

作者：

Dutta, P

Manivannan, A

Seehra, MS ^{[1
]}

Adekkanattu, PM

Guin, JA

机构：

[1] W Virginia Univ, Dept Phys, Morgantown, WV 26506 USA

[2] Auburn Univ, Dept Chem Engn, Auburn, AL 36849 USA

来源：

CATALYSIS LETTERS | 2004年 / 94卷 / 3-4期

关键词：

SAPO-n molecular sieves; nickel species; magnetization; magnetic susceptibility;

D O I：

10.1023/B:CATL.0000020543.63517.c4

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：

A method to determine the electronic state and concentration of Ni in Ni-loaded silicoaluminophosphate (NiSAPO-n) where n denotes the structure type ( n = 47, 18, 34, 44, 56 and 17) is presented. The method involves measurements and analysis of the magnetization M versus magnetic field H ( up to 55 kOe at 2 K) and M versus temperature ( T = 2 - 300 K) data. The analysis yields spin S = 1/2 corresponding to Ni( I) state for lightly doped samples, whereas for higher doping, both Ni( I) and Ni( 0) are indicated. The concentration of Ni determined from these studies varies between the minimum of 0.2 wt% for the n = 47 sample to maximum of 1.75% for the n = 17 sample.

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页码：181 / 185

页数：5

相关论文

共 18 条

[1] SMALL-PORE MOLECULAR-SIEVES SAPO-34 AND SAPO-44 WITH CHABAZITE STRUCTURE - A STUDY OF SILICON INCORPORATION [J].

ASHTEKAR, S ;

CHILUKURI, SVV ;

CHAKRABARTY, DK .

JOURNAL OF PHYSICAL CHEMISTRY, 1994, 98 (18) :4878-4883

[2] ELECTRON-SPIN-RESONANCE AND ELECTRON-SPIN ECHO MODULATION STUDIES OF NI(I) IN SILICOALUMINOPHOSPHATE TYPE-11 - REDUCIBILITY AND LOCATION OF NICKEL IONS DURING VARIOUS DEGREES OF DEHYDRATION [J].

AZUMA, N ;

KEVAN, L .

JOURNAL OF PHYSICAL CHEMISTRY, 1995, 99 (14) :5083-5088

[3] SAPO-18 CATALYSTS AND THEIR BRONSTED ACID SITES [J].

CHEN, JS ;

WRIGHT, PA ;

THOMAS, JM ;

NATARAJAN, S ;

MARCHESE, L ;

BRADLEY, SM ;

SANKAR, G ;

CATLOW, CRA ;

GAIBOYES, PL ;

TOWNSEND, RP ;

LOK, CM .

JOURNAL OF PHYSICAL CHEMISTRY, 1994, 98 (40) :10216-10224

[4] Catalytic study of methanol-to-olefins conversion in four small-pore silicoaluminophosphate molecular sieves: Influence of the structural type, nickel incorporation, nickel location, and nickel concentration [J].

Djieugoue, MA ;

Prakash, AM ;

Kevan, L .

JOURNAL OF PHYSICAL CHEMISTRY B, 2000, 104 (27) :6452-6461

[5] Conversion of methanol to olefins over cobalt-, manganese- and nickel-incorporated SAPO-34 molecular sieves [J].

Dubois, DR ;

Obrzut, DL ;

Liu, J ;

Thundimadathil, J ;

Adekkanattu, PM ;

Guin, JA ;

Punnoose, A ;

Seehra, MS .

FUEL PROCESSING TECHNOLOGY, 2003, 83 (1-3) :203-218

[6] Synthesis optimization of chabasite-like SAPO-47 in the presence of sec-butylamine [J].

Dumitriu, E ;

Lutic, D ;

Hulea, V ;

Dorohoi, D ;

Azzouz, A ;

Colnay, E ;

Kappenstein, C .

MICROPOROUS AND MESOPOROUS MATERIALS, 1999, 31 (1-2) :187-193

[7] Transition-metal ions in aluminophosphate and silicoaluminophosphate molecular sieves: Location, interaction with adsorbates and catalytic properties [J].

Hartmann, M ;

Kevan, L .

CHEMICAL REVIEWS, 1999, 99 (03) :635-663

[8]

KITTEL C, 1996, INTRO SOLID STATE PH, P417

[9]

Lok B. M., 1984, US Patent, Patent No. 4440871

[10] SYNTHESIS OF SAPO-34 - HIGH-SILICON INCORPORATION IN THE PRESENCE OF MORPHOLINE AS TEMPLATE [J].

PRAKASH, AM ;

UNNIKRISHNAN, S .

JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS, 1994, 90 (15) :2291-2296