An in situ temperature dependent IR, EPR and high resolution XANES study on the NO/Cu+-ZSM-5 interaction

被引：94

作者：

Prestipino, C

Berlier, G

Xamena, FXLI

Spoto, G

Bordiga, S

Zecchina, A

Palomino, GT

Yamamoto, T

Lamberti, C

机构：

[1] Univ Turin, IFM, Dipartimento Chim, I-10125 Turin, Italy

[2] Univ Turin, INFM, UdR, Turin, Italy

[3] Univ Turin, INSTM, UdR, Turin, Italy

[4] Univ Balearic Isl, Dept Quim, Palma de Mallorca 07071, Spain

[5] Kyoto Univ, Dept Mol Engn, Grad Sch Engn, Kyoto 6068501, Japan

来源：

CHEMICAL PHYSICS LETTERS | 2002年 / 363卷 / 3-4期

关键词：

D O I：

10.1016/S0009-2614(02)01183-1

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：

We report an in situ IR, EPR, and high resolution XANES study on the Cu+(NO) and Cu+(NO)(2) complexes formed at 80 K in Cu+-ZSM-5. Bare Cu2+ ions (<1%) exhibit an axial EPR spectrum, while bare Cu+ ions exhibit well resolved 1s --> 4p(xy) and 1s --> 4p(z) transitions (p(xy)/p(z) splitting of 3.1 eV), reflecting the same local symmetry. Cu+(NO) complex exhibits an anisotropic EPR signal, while XANES spectrum of dinitrosyl adducts presents three resolved components ascribed to the 1s --> 4p(x), 1s --> 4p(y), and 1s --> 4p(z) transitions (p(x)/p(y) and p(y)/p(z) splitting of 3.8 and 2.6 eV, respectively) testifying the rupture of the axial symmetry of Cu+ bare cations upon NO adsorption. Upon increasing the temperature to 300 K, NO oxidizes a fraction of 75-85% of the cuprous ions. (C) 2002 Elsevier Science B.V. All rights reserved..

引用

页码：389 / 396

页数：8

共 37 条

[1] Mechanistic cause of hydrocarbon specificity over Cu/ZSM-5 and Co/ZSM-5 catalysts in the selective catalytic reduction of NOx [J].