Effect of the particle size and surface area of tungstated zirconia on the WOx nuclearity and n-heptane isomerization over Pt/WO3–ZrO2

0358979 - ÚFCH JH 2012 RIV NL eng J - Journal Article
Kaucký, Dalibor - Wichterlová, Blanka - Dědeček, Jiří - Sobalík, Zdeněk - Jakubec, Ivo
Effect of the particle size and surface area of tungstated zirconia on the WOx nuclearity and n-heptane isomerization over Pt/WO3–ZrO2.
Applied Catalysis A - General. Roč. 397, 1-2 (2011), s. 82-93. ISSN 0926-860X. E-ISSN 1873-3875
R&D Projects: GA AV ČR KAN100400702
Institutional research plan: CEZ:AV0Z40320502; CEZ:AV0Z40400503
Keywords : n-heptane isomeration * Pt/WO3-ZrO2 * nano ZrO2
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 3.903, year: 2011

Four series of tungstated zirconia of different surface area ranging from 100 to 20 m2 g−1 and of micro- and nano-meter crystal size were investigated with respect to nuclearity and reducibility of WOx species, concentration of strong and weak acid sites, and n-heptane isomerization over Pt/WO3–ZrO2. The nuclearity of WOx species was analyzed by diffuse reflectance UV–Vis spectroscopy and their reducibility by TPR-H2. TPD of ammonia distinguished acid sites of different strengths. n-Heptane isomerization proceeds over Pt/WO3–ZrO2 in hydrogen/nitrogen mixture at 250 °C. At least four types of WOx species differing in nuclearity were identified in tungstated zirconia by a maxima of absorption at 39 000, 35 000, 30 000 and 27 000 cm−1, intensity of which depended on the surface area, crystal size and WO3 loading.
Permanent Link: http://hdl.handle.net/11104/0006415