Selective oxidative dehydrogenation of ethane over SnO2-promoted NiO catalysts
Sn-doped NiO catalysts are highly efficient for the oxidative dehydrogenation of ethane. Addition of a tiny amount of tin highly increases selectivity to ethylene. [Display omitted] ► NiSnO mixed oxides catalysts for ethane ODH were prepared and investigated. ► Addition of a tiny amount of tin highl...
Saved in:
Published in: | Journal of catalysis Vol. 295; pp. 104 - 114 |
---|---|
Main Authors: | , , , , , , |
Format: | Journal Article |
Language: | English |
Published: |
Amsterdam
Elsevier Inc
01-11-2012
Elsevier Elsevier BV |
Subjects: | |
Online Access: | Get full text |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Summary: | Sn-doped NiO catalysts are highly efficient for the oxidative dehydrogenation of ethane. Addition of a tiny amount of tin highly increases selectivity to ethylene. [Display omitted]
► NiSnO mixed oxides catalysts for ethane ODH were prepared and investigated. ► Addition of a tiny amount of tin highly increases selectivity to ethylene. ► Changes in the nature of Ni species on the surface of catalysts are observed. ► Changes in the crystal size of NiO particles with Sn-loading are observed.
NiSnO mixed oxides catalysts have been investigated for the oxidative dehydrogenation of ethane. The catalysts were prepared through the evaporation of aqueous solutions of nickel nitrate and tin oxalate and finally calcined in air at 500°C for 2h. These materials have been characterized by several techniques (N2-adsorption, X-ray diffraction, High-Resolution Electron Microscopy, temperature programmed reduction, X-Ray Photoelectron Spectroscopy, Fourier Transformed Infrared Spectroscopy of adsorbed CO and 18O/16O isotope exchange). The addition of just a tiny amount of tin highly increases the selectivity to ethylene (from ca. 40% to 80–90%). Thus, high selectivity to ethylene (near to 90%) is observed on samples with high Ni/Sn atomic ratios (3<Ni/Sn<50), in which no influence of ethane conversion on selectivity to ethylene is observed (suggesting high stability of ethylene on these catalysts). Additionally, for low Sn-loadings, an increase in the catalytic activity has also been observed. The enhanced catalytic properties have been explained in terms of changes in the nature of Ni species on the catalyst surface, which can be considered as the active sites. The nature of Ni species is related to changes in the crystal size of NiO particles (and surface area) of catalysts as well as to the presence of SnOx crystals. In addition, the role of the presence of acid sites on the catalyst surface on the selectivity to ethylene is also discussed. |
---|---|
Bibliography: | http://dx.doi.org/10.1016/j.jcat.2012.07.028 |
ISSN: | 0021-9517 1090-2694 |
DOI: | 10.1016/j.jcat.2012.07.028 |