Abstract

The changes of structure and electronic state of copper ion species during the heat treatment of copper ion-exchanged ZSM-5 zeolite (CuZSM-5) as well as the interaction with CO molecules have been investigated by using various spectroscopic techniques such as infrared (IR) and emission spectroscopy (ES), electron spin resonance (ESR), and X-ray absorption fine structure (XAFS) consisting of a XANES (X-ray absorption near edge structure) and an EXAFS (extended X-ray absorption fine structure) and through the measurements of heat of adsorption and adsorption isotherm. About 70% of the divalent copper ions (Cu2+) exchanged in CuZSM-5 were found to be reduced to the monovalent copper ions (Cu+) during the heat treatment at 873 K in vacuo, the latter species having a linear or a planar coordination structure with a coordination number of 2 or 3 with respect to the nearest-neighboring oxygen atoms at a distance of 1.98 A. It was found from the ES data that the Cu+ species strongly interact with CO molecules at ...

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 call

Disclaimer: 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.