Oxidative dehydrogenation of n-butane on Cs doped nickel molybdate: Kinetics and mechanism

被引：17

作者：

Madeira, LM ^{[1
]}

MaldonadoHodar, FJ ^{[1
]}

Portela, MF ^{[1
]}

Freire, F ^{[1
]}

MartinAranda, RM ^{[1
]}

Oliveira, M ^{[1
]}

机构：

[1] UNIV TECN LISBOA, INST SUPER TECN, GRP ESTUDOS CATALISE HETEROGENEA, P-1096 LISBON, PORTUGAL

来源：

APPLIED CATALYSIS A-GENERAL | 1996年 / 135卷 / 01期

关键词：

butane dehydrogenation; cesium doping; kinetics; nickel molybdate;

D O I：

10.1016/0926-860X(95)00203-0

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 oxidative dehydrogenation of n-butane over a highly selective catalyst (3% Cs doped alpha-NiMoO4) has been studied in order to understand the mechanism of the reaction. The catalyst characterization was carried out by BET, X-ray diffraction (XRD), coupled plasma spectroscopy (ICP), atomic absorption (AA), X-ray fluorescence (XRF), IR and X-ray photoelectron spectroscopy (XPS). All the results showed an atomic ratio of Mo/Ni = 1 and a cesium surface concentration of 3%. The kinetic tests were carried out between 773 and 833 K changing the contact time and the partial pressure of both butane and oxygen. Only dehydrogenation products (1-butene, 2-butenes (cis and trans) and butadiene) and CO and CO2 were observed under all experimental conditions. The experimental results can be correlated using a redox model. Two active sites were observed by CO2-TPD, which would be responsible for the formation of two different adsorbed intermediates of butane. It is proposed that in the more basic sites 1-butene would be formed which reacts partially to butadiene and in the less basic sites the formation of the 2-butene isomers would occur.

引用

页码：137 / 153

页数：17