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Acid Sites in HZSM-5 Upon Copper Exchange by FTIR and DSC Using Ammonia

2001; Wiley; Volume: 24; Issue: 3 Linguagem: Inglês

10.1002/1521-4125(200103)24

1521-4125

Goran Bošković, Tatjana Vulić, Erne Kiš, П. Путанов,

Catalysis and Hydrodesulfurization Studies

Chemical Engineering & TechnologyVolume 24, Issue 3 p. 269-274 Full Paper Acid Sites in HZSM-5 Upon Copper Exchange by FTIR and DSC Using Ammonia G. Boskovic, G. BoskovicSearch for more papers by this authorT. Vulic, T. Vulic University of Novi Sad, Faculty of Technology, 21000 Novi Sad, YugoslaviaSearch for more papers by this authorE. Kis, E. Kis University of Novi Sad, Faculty of Technology, 21000 Novi Sad, YugoslaviaSearch for more papers by this authorP. Putanov, P. Putanov Serbian Academy of Sciences and Arts, 11000 Beograd, YugoslaviaSearch for more papers by this author G. Boskovic, G. BoskovicSearch for more papers by this authorT. Vulic, T. Vulic University of Novi Sad, Faculty of Technology, 21000 Novi Sad, YugoslaviaSearch for more papers by this authorE. Kis, E. Kis University of Novi Sad, Faculty of Technology, 21000 Novi Sad, YugoslaviaSearch for more papers by this authorP. Putanov, P. Putanov Serbian Academy of Sciences and Arts, 11000 Beograd, YugoslaviaSearch for more papers by this author First published: 07 March 2001 https://doi.org/10.1002/1521-4125(200103)24:3 3.0.CO;2-PCitations: 9AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Abstract The acidity of the parent HZSM-5 zeolite and Cu-HZSM-5 catalyst has been examined by FTIR and DSC using ammonia desorption. Sites of different strength were found in HZSM-5, desorbing ammonia at a relative temperature difference of about 100 °C. Upon copper exchange a fraction of Brønsted sites were transformed to Lewis sites, but the acid strength of the remaining Brønsted sites was increased. Aside from Lewis sites originating from copper exchange, there might be some additional sites formed from precipitated copper. This could explain the quantity of adsorbed NH3 on Cu-ZSM-5 which is higher than theoretically expected. While changing their nature, acid sites of higher strength keep their location, which is manifested by some diffusion effect towards ammonia. Citing Literature Volume24, Issue3March 2001Pages 269-274 RelatedInformation