Oxidation of ethane to ethylene and acetic acid by MoVNbO catalysts

• Published in: Catalysis today Vol. 99; no. 1; pp. 77 - 87
• Main Authors: Roussel, M., Bouchard, M., Bordes-Richard, E., Karim, K., Al-Sayari, S.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.01.2005; Elsevier Science; Elsevier
• Subjects: Acetic acid; Catalysis; Chemical Sciences; Chemistry; Ethylene; Exact sciences and technology; General and physical chemistry; Mild oxidation of ethane; MoVNbO catalysts; Nanosized (VNbMo) 5O 14; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Acetic acid; Mild oxidation of ethane; Nanosized (VNbMo) 5O 14; MoVNbO catalysts; Ethylene; Transition metal Compounds; Nanosized (VNbMO)5O14; Vanadium Oxides; Ethane; Heterogeneous catalysis; Quaternary compound; Niobium Oxides; Carboxylic acid; Oxidation; Molybdenum Oxides; Catalyst; nanosized (VNbMo)5O14; ethylene; acetic acid; mild oxidation of ethane
• ISSN: 0920-5861; 1873-4308
• DOI: 10.1016/j.cattod.2004.09.026

The influence of niobium on the physicochemical properties of the Mo V O system and on its catalytic properties in the oxidation of ethane to ethylene and acetic acid is examined. Solids based on MoV 0.4O x and MoV 0.4Nb 0.12O y composition and calcined at 350 or 400 °C were studied by X-ray diffraction, and by laser Raman and X-ray photoelectron spectroscopies. Their reactivity during reduction and reoxidation was examined by in situ XRD and by XPS after pre-treatment. Their stability in air was evaluated by means of Raman spectroscopy during laser heating of particles. Niobium is responsible for both stabilization and nanosize of MoO 3 and (VNbMo) 5O 14 crystals. The high global selectivity to ethylene and acetic acid (90–96 mol%) is related to the presence of both phases while higher activity is owed to nanoparticles. The model already proposed by Merzouki et al. (Stud. Surf. Sci. Catal., 72 (1992) 81) suggesting that MoVNbO catalysts could be made up from (VNbMo) 5O 14-type microdomains in MoO 3 matrix seems still topical.