Abstract
Alumina-supported indium oxide (In 2O 3) catalysts with In loadings between 2 and 22 wt% were prepared by impregnation and characterized for their main properties. Surface properties, such as the surface area; surface In content, measured by X-ray photoelectron spectroscopy (XPS); and acidity and basicity, measured both by adsorption microcalorimetry using ammonia and sulfur dioxide as probe molecules and by infrared spectroscopy of pyridine adsorption, were determined. Bulk properties, namely the crystallographic structure as determined by powder X-ray diffraction (XRD) analysis and the redox character of the In 2O 3-dispersed phase as determined by redox cycles performed both in a flow apparatus and in a thermobalance coupled with a differential scanning microcalorimeter (TG-DSC), were studied. The results obtained were interpreted in terms of In 2O 3 surface dispersion or aggregation. The catalysts tested in the reduction of NO x by ethene in an oxygen-rich atmosphere showed an interesting ability to selectively reduce NO x to N 2, independently of the In loading. The weakness of the oxidative properties of the In 2O 3 phases limited the ethene combustion and made the catalysts able to reduce NO x even at high temperature (up to 550 °C). The rates of nitrogen formation depended strongly on the In 2O 3 aggregation state; the In centers were very active even at low amounts.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
