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Localization and Speciation of Iron Impurities within a Fluid Catalytic Cracking Catalyst
Author(s) -
Ihli Johannes,
Ferreira Sanchez Dario,
Jacob Rosh R.,
Cuartero Vera,
Mathon Olivier,
Krumeich Frank,
Borca Camelia,
Huthwelker Thomas,
Cheng WuCheng,
Shu YuYing,
Pascarelli Sakura,
Grolimund Daniel,
Menzel Andreas,
van Bokhoven Jeroen A.
Publication year - 2017
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201707154
Subject(s) - catalysis , impurity , fluid catalytic cracking , ferrous , chemical engineering , petrochemical , porosity , iron oxide , particle (ecology) , zeolite , materials science , cracking , chemistry , inorganic chemistry , metallurgy , composite material , organic chemistry , geology , oceanography , engineering
Abstract Fluid catalytic cracking is a chemical conversion process of industrial scale. This process, utilizing porous catalysts composed of clay and zeolite, converts heavy crude‐oil fractions into transportation fuel and petrochemical feedstocks. Among other factors iron‐rich reactor and feedstream impurities cause these catalyst particles to permanently deactivate. Herein, we report tomographic X‐ray absorption spectroscopy measurements that reveal the presence of dissimilar iron impurities of specific localization within a single deactivated particle. Whereas the iron natural to clay in the composite seems to be unaffected by operation, exterior‐facing and feedstream‐introduced iron was found in two forms. Those being minute quantities of ferrous oxide, located near regions of increased porosity, and impurities rich in Fe 3+ , preferentially located in the outer dense part of the particle and suggested to contribute to the formation of an isolating amorphous silica alumina envelope.