Pergamon Materials Research Bulletin, Vol. 31,No.5, pp.513-520,1996 Copyright O 1996 Elsevier Seienoe Ltd Printed intheUSA. Allrights reserved 0025-5408/96 $15.00 + .00 PII S0025-5408(96)00029-3 VANADIA-TITANIA SYSTEMS: MORPHOLOGICAL AND STRUCTURAL PROPERTIES L. J. Alemany I, M. A. Bafiares 2, M. A. Larrubia 1, M. C. Jim6nez I, F. Delgado I and J. M. Blasco ! (1) Departamento de Ingenieda Quimica, Universidad de Mfilaga, Campus de Teatinos, 29071 M~aga, Spain. (2) Instituto de Cat~disis y Petroleoquimiea, CSIC, Campus UAM, Cantoblaneo, 28049 Madrid, Spain. (Received June 5, 1995; Accepted December 28, 1995) (Refereed) ABSTRACT The changes of structure of TiO2 in line with vanadium loading and thermal treatment have been studied. A correlation is proposed between vanadium surface coverage, crystal size and the Raman intensity. Modification of anatase cell parameters by vanadium substitution is reported. KEYWORDS: A. oxides, C. Raman spectroscopy, C. X-ray diffraction, D. crystal structure INTRODUCTION Many investigations have been published on the characteristics of vanadia-titania catalysts in the current literature (1-7). The structure and reactivity have been extensively studied, but the influence of vanadia on the structural and morphological evolution has been less studied (8, 9). In this paper we present an investigation on the influence of temperature and the vanadium loading on the morphological and structural properties of the vanadia-titania catalytic systems, A correlation is attempted between the microscopic properties of material and the macroscopic morphological and structural ones. EXPERIMENTAL Pure TiO 2 and V205-TiO 2 samples have been prepared and characterized. Pure TiO2 has been obtained by neutralization at a pH constant (pH = 6) of an acid solution of high purity grade 513