Abstract
X-ray photoelectron spectroscopy was applied to investigate Pt/NaY, Co/NaY and Pt-Co/NaY zeolites prepared by ion exchange (IE) and impregnation (IM). Changes in the electronic states and surface distribution of sodium and silicon were followed in NaY and in Pt and Co containing NaY in the as prepared (AP), calcined (OX) and reduced (RE) states. Decoration of the zeolite surface by alumina detected, is attributed to the local processes during ion exchange. Introduction of Co 2+ ions into the Pt-containing samples influences the electronic states of platinum both in calcined and reduced state. Pt° facilitates reduction of Co 2+ ions and formation of bimetallic Pt-Co particles within the zeolite supercages could also be evidenced. The results support earlier TPR measurements indicating the presence of very small Pt-Co bimetallic particles for (IE) samples. On the other hand, in the impregnated NaY no sodium exchange occurs and the transition-metal species are located at the external surface of NaY zeolites.
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.
