Preparation, crystal structure, thermal and catalytical behaviour of copper diammine divanadate

• Published in: Materials research bulletin 1993, Vol.28 (1), p.45-58
• Main Authors: Aschwanden, S., Schmalle, H.W., Reller, A., Oswald, H.R.
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Inorganic compounds; Metal complexes; Physics; Structure of solids and liquids; crystallography; Structure of specific crystalline solids
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/0025-5408(93)90007-Z

A new copper diammine divanadate Cu(NH 3) 2(VO 3) 2 has been synthesized and structurally characterized. The unit cell is monoclinic, space group Pc, a = 5.616(2) A ̊ , b = 5.591(1) A ̊ , c = 11.331(2) A ̊ , β = 90.91(2)°, V = 355.7(3) A ̊ 3 , Z = 2. The thermal decomposition has been studied by thermogravimetry and simultaneous mass spectrometry (TG/MS) in different atmospheres, i.e. H 2, N 2, He and O 2. As solid products elemental copper on V 2O 3, Cu 0.95V 2O 5 and CuV 2O 6 have been obtained, and depending on the actual atmosphere different volatile products such as NH 3, H 2O and N 2. Independent of the pretreatment, reoxidation of the product phases leads to the ternary oxide CuV 2O 6. The microstructures have been characterized by scanning electron microscopy (SEM) and high resolution electron microscopy (HREM). The product decomposed in hydrogen has been tested with respect to its catalytic activity for the reduction of NO with CO.