Direct multi-elemental imaging of freshly impregnated catalyst by Laser-Induced Breakdown Spectroscopy

Abstract

The preparation step of a catalyst is of primary importance as it may govern its performance. We report here the first direct multi-elemental imaging of an alumina-supported catalyst during the maturation process. Alumina extrudate support was impregnated with a nickel nitrate solution in the presence of citric acid as an organic additive. Wet extrudates were sampled, cut in half and imaged by Laser-Induced Breakdown Spectroscopy (LIBS) for varying maturation times. Results were validated by comparison with more conventional techniques such as Raman and Magnetic Resonance Imaging. This communication demonstrates the speed of acquisition, low detection limits and multi-elemental capabilities of LIBS to provide valuable information to understand the phenomena occurring during catalyst impregnation. The proposed approach allows one to shorten drastically the analysis time (by a factor of 30) and emphasizes LIBS imaging potential as a unique characterization technique able to simultaneously monitor the distribution of the metallic precursor, organic additive and support impurities.