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Measuring system for obtaining concentration profiles in supported catalysts using electron‐probe microanalysis. Influence of standards
Author(s) -
Viturro H.,
Bonetto R. D.,
Pizzio L. R.,
Vázquez P. G.,
Sanchez M.,
Alvarez A. G.
Publication year - 1995
Publication title -
x‐ray spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.447
H-Index - 45
eISSN - 1097-4539
pISSN - 0049-8246
DOI - 10.1002/xrs.1300240103
Subject(s) - analyser , radius , tungsten , electron probe microanalysis , spheres , particle (ecology) , microanalysis , materials science , analytical chemistry (journal) , catalysis , chemistry , metallurgy , electron microprobe , computer science , physics , chromatography , geology , biochemistry , computer security , oceanography , organic chemistry , astronomy
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–γ‐Al 2 O 3 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.