Catalyst Deactivation in Fluid Catalytic Cracking
Fluid catalytic cracking (FCC), an important process in chemical industry, converts the heavy fractions of crude oil into valuable petrol and chemicals. The catalyst is a spherical composite of zeolite and clay that decreases in catalytic activity during long-term operation. By using a range of electron microscopy and elemental mapping techniques, the structural and chemical characteristics of pristine and progressively deactivated catalyst particles have been characterized from the micro- down to the nanometer scale. An increasingly dense amorphous silica alumina layer wrapping the particles is formed during operation. Fe and Ca are the main impurities in this envelope.
A three-dimensional view of structural changes caused by deactivation of fluid catalytic cracking catalysts
J. Ihli, R. R. Jacob, M. Holler, M. Guizar Sicairos, A. Diaz, J. C. da Silva, D. Ferreira Sanchez, F. Krumeich, D. Grolimund, M. Taddei, W.-C. Cheng, Y. Y. Shu, A. Menzel, and J. A. van Bokhoven
Nature Commun. 2017, 8, 809, DOI
Localization and Speciation of Iron Impurities within a Fluid Catalytic Cracking Catalyst
J. Ihli, D. Ferreira Sanchez, J. Rosh, V. Cuartero, O. Mathon, F. Krumeich, C. Borca, T. Huthwelker, W.-C. Cheng, Y.-Y. Shu, S. Pascarelli, D. Grolimund, A. Menzel, and J. A. van Bokhoven
Angew. Chem. Int. Ed. 2017, 56, 14031-14035, DOI