Localization and Speciation of Iron Impurities within a Fluid Catalytic Cracking Catalyst. Issue 45 (5th October 2017)

• Record Type: Journal Article
• Authors: Ihli, Johannes; Ferreira Sanchez, Dario; Jacob, Rosh R.; Cuartero, Vera; Mathon, Olivier; Krumeich, Frank; Borca, Camelia; Huthwelker, Thomas; Cheng, Wu‐Cheng; Shu, YuYing; Pascarelli, Sakura; Grolimund, Daniel; Menzel, Andreas; van Bokhoven, Jeroen A.
• Is Part Of: Angewandte Chemie international edition. Volume 56:Issue 45(2017)
• Page Start: 14031
• Page End: 14035
• Publication Date: 2017-10-05
• Subjects: fluid catalytic cracking -- heterogeneous catalysis -- tomography -- XANES -- X-ray absorption spectroscopy; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201707154
• Languages: English
• ISSNs: 1433-7851

Abstract

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. Abstract : Finding iron : Tomographic X‐ray absorption spectroscopy at the Fe K‐edge allows the visualization of distinct iron impurities of specific localization within a single deactivated fluid catalytic cracking catalyst particle. The spatial localization in combination with the nature of the iron impurities is in agreement with a multimodal deactivation process.