0181761 - UFCH-W 20030200 RIV NL eng J - Journal Article
Sobalík, Zdeněk - Tvarůžková, Zdenka - Wichterlová, Blanka - Fíla, V. - Špatenka, Š.
Acidic and Catalytic Properties of Mo-MCM-22 in Methane Aromatization: An FTIR Study.
Applied Catalysis A - General. Roč. 253, - (2003), s. 271-282. ISSN 0926-860X. E-ISSN 1873-3875
R&D Projects: GA ČR GA104/99/0432
Institutional research plan: CEZ:AV0Z4040901
Keywords : methane aromatization * FTIR technique * MCM-22
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 2.825, year: 2003

Acidity investigation of fresh and used Mo/MCM-22 catalyst for methane aromatization is presented. Determination of Bronsted acidity, connected with bridged OH groups, and Lewis acidity, related to Al was obtained using quantitative analysis of FTIR technique and employing d3-acetonitrile as the probe molecule. Acidity changes for both the parent zeolite and Mo-containing zeolite were analyzed in individual periods of the catalyst development in the methane stream, i.e. during the activation period (up to 70 min), at the optimum performance (between 70-150 min), during catalyst deactivation (up to 10 hours), and after its regeneration in oxygen. Both, the bridged hydroxyls (conc. 0.21 mmol/g) and Lewis acidic sites (two types; total conc. 0.14 mmol/g) were present in the parent HMCM-22 zeolite. Molybdenum incorporation induced a decrease in concentration of bridged OH groups to about one half of its original value after calcinations at 450 oC, while the Lewis sites content.
Permanent Link: http://hdl.handle.net/11104/0001935