Effect of Phosphate Modification on the Brønsted Acidity and Methanol‐to‐Olefin Conversion Activity of Zeolite ZSM‐5. Issue 11 (23rd August 2013)

• Record Type: Journal Article
• Authors: Dyballa, Michael; Klemm, Elias; Weitkamp, Jens; Hunger, Michael
• Is Part Of: Chemie Ingenieur Technik. Volume 85:Issue 11(2013:Nov.)
• Page Start: 1719
• Page End: 1725
• Publication Date: 2013-08-23
• Subjects: Chemical engineering -- Patents -- Periodicals; Chemical engineering -- Periodicals; Chemical industry -- Periodicals; Chemistry, Technical -- Periodicals; 660.05
• DOI: 10.1002/cite.201300066
• Languages: English
• ISSNs: 0009-286X

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Phosphate‐modified ZSM‐5 zeolites were studied by standard characterization techniques and solid‐state nuclear magnetic resonance spectroscopy, and in the methanol‐to‐olefin (MTO) conversion. Considering the physicochemical properties of the ZSM‐5 zeolites, the most important effects of the phosphate modification are a deposition of polyphosphates in the pore system and a decrease of the acid site density, but not of the acid site strength. The significant increase in the selectivity to C₂ – C₄ alkenes and the decrease of C₅₊ formation in the MTO reaction for a phosphate coverage of about 5 wt % are explained by extra‐framework phosphate species near the crossing intersections of the ZSM‐5 pore system, which hinder the formation of large intermediates and reaction products.</p> </abstract>