"Measuring system to obtaining concentration profiles in supported catalysts using an electron-probe microanalysis. Influence of standards".

H. VITURRO; R. BONETTO; L. PIZZIO; P. VÁZQUEZ; M. SÁNCHEZ; G. ALVAREZ

X-RAY SPECTROMETRY

Wiley InterScience

Año: 1995 vol. 24 p. 3 - 10

0049-8246

A system based on the EDAX 9100 analyser was developed to obtain concentration profiles. Even though the system can be used on any type of flat specimens, in this study it was used for measuring the tungsten (W) concentration on rough spherical specimens of the W- -Al2O3 supported catalyst. The concentration gradient of the active component from the periphery to the centre of the particle is often an important factor in determining catalyst performance. The purpose was to determine the concentration profile of W along the radius of a sphere with a large enough number of experimental points to draw accurate information in a short time. In this way, a considerable number of impregnated spheres can be analysed, and average results can be calculated and taken as representative values of the population under study. The method developed provides highly satisfactory results, making it very useful for the systematic study of this type of specimen. Obviously, the use of this system can be extended to metallurgical and mineralogical specimens.