Effect of ceria on the structure and catalytic activity of V2O5/TiO2–ZrO2 for oxidehydrogenation of ethylbenzene to styrene utilizing CO2 as soft oxidant

• Published in: Applied catalysis. B, Environmental Vol. 91; no. 3-4; pp. 649 - 656
• Main Authors: Rao, Komateedi N., Reddy, Benjaram M., Abhishek, B., Seo, Yeong-Hui, Jiang, Nanzhe, Park, Sang-Eon
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 28.09.2009; Elsevier
• Subjects: Carbon dioxide; Catalysis; Chemistry; Ethylbenzene; Exact sciences and technology; General and physical chemistry; Oxidative dehydrogenation; Styrene; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; V2O5/TiO2–ZrO2; Ethylbenzene; Oxidative dehydrogenation; V2O5/TiO2–ZrO2; Carbon dioxide; Styrene; Binary compound; Catalytic reaction; Hydrocarbon; Transition element compounds; Oxidant; Cerium oxide; O; Lanthanide compound; Heterogeneous catalysis; Zirconium oxide; Dehydrogenation; V; ZrO; Benzenic compound; Vanadium oxide; Oxidation; TiO; Titanium oxide; Structure; Environmental protection
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2009.07.003

The present study was undertaken to investigate the influence of ceria on the physicochemical and catalytic properties of V2O5/TiO2–ZrO2 for oxidative dehydrogenation of ethylbenzene to styrene utilizing CO2 as a soft oxidant. Monolayer equivalents of ceria, vanadia and ceria–vanadia combination over TiO2–ZrO2 (TZ) support were impregnated by a coprecipitation and wet impregnation methods. Synthesized catalysts were characterized by using X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, temperature programmed reduction, transmission electron microscopy and BET surface area methods. The XRD profiles of 550°C calcined samples revealed amorphous nature of the materials. Upon increasing calcination temperature to 750°C, in addition to ZrTiO4 peaks, few other lines due to ZrV2O7 and CeVO4 were observed. The XPS V 2p results revealed the existence of V4+ and V5+ species at 550 and 750°C calcinations temperatures, respectively. TEM analysis suggested the presence of nanosized (<7nm) particles with narrow range distribution. Raman measurements confirmed the formation ZrTiO4 under high temperature treatments. TPR measurements suggested a facile reduction of CeO2–V2O5/TZ sample. Among various samples evaluated, the CeO2–V2O5/TZ sample exhibited highest conversion and nearly 100% product selectivity. In particular, the addition of ceria to V2O5/TZ suppressed the coke deposition and allowed a stable and high catalytic activity.