Electron Optical Studies of Fresh and Reduced Vanadium Pentoxide-Supported Rhodium Catalysts

• Published in: Journal of catalysis Vol. 140; no. 1; pp. 173 - 183
• Main Authors: Legrouri, A., Baird, T., Fryer, J.R.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.03.1993; Elsevier
• Subjects: 400201 - Chemical & Physicochemical Properties; ABSORPTION SPECTROSCOPY; Catalysis; CATALYST SUPPORTS; CATALYSTS; Catalysts: preparations and properties; CHALCOGENIDES; CHEMICAL REACTIONS; Chemistry; COHERENT SCATTERING; DIFFRACTION; ELECTRON MICROSCOPY; Exact sciences and technology; General and physical chemistry; IMPREGNATION; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; MICROSCOPY; OXIDES; OXYGEN COMPOUNDS; REDUCTION; REFRACTORY METAL COMPOUNDS; RHODIUM COMPOUNDS; SCATTERING; SPECTROSCOPY; STRUCTURAL CHEMICAL ANALYSIS; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE; TEMPERATURE RANGE 0400-1000 K; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; TRANSITION ELEMENT COMPOUNDS; TRANSMISSION ELECTRON MICROSCOPY; VANADIUM COMPOUNDS; VANADIUM OXIDES; X-RAY DIFFRACTION; Scanning electron microscopy; Transition metal; Experimental study; X ray diffraction; Supported catalyst; Characterization; Chemical reduction; Infrared spectrometry; Programmed temperature; Heterogeneous catalysis; Impregnation; Transmission electron microscopy; Vanadium V Oxides; Rhodium; Preparation; Platinoid
• DOI: 10.1006/jcat.1993.1076
• ISSN: 0021-9517

One percent Rh/V 2O 5 catalysts prepared by wet impregnation with RhCl 3 · xH 2O and subsequent reduction in hydrogen were shown to be subject to the formation of lower oxides of vanadium via an Rh-catalysed reduction process. V 4O 9, VO 2, and V 2O 3 compounds were observed at reduction temperatures of 250, 450, and 600°C, respectively, as characterised by IR, XRD, and electron optical methods. Maximum hydrogen uptake by the Rh-loaded V 2O 5 occurred at 155°C according to TPR data, and this contrasts with the onset of reduction of V 2O 5 alone at ∼450°C. Mechanistic and structural aspects of the Rh-catalysed reduction process are discussed.