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Updated: Mar 22, 2026

A Continuous-flow Photocatalytic Reactor for the Precisely Controlled Deposition of Metallic Nanoparticles
Published on: April 10, 2019
Nanoscale Chemical Imaging of an Individual Catalyst Particle with Soft X-ray Ptychography
Anna M Wise1, Johanna Nelson Weker1, Sam Kalirai2
1Stanford Synchrotron Radiation Lightsource, Stanford University , Menlo Park, California 94025, United States.
Abstract:
Understanding Fe deposition in fluid catalytic cracking (FCC) catalysis is critical for the mitigation of catalyst degradation. Here we employ soft X-ray ptychography to determine at the nanoscale the distribution and chemical state of Fe in an aged FCC catalyst particle. We show that both particle swelling due to colloidal Fe deposition and Fe penetration into the matrix as a result of precracking of large organic molecules occur. The application of ptychography allowed us to provide direct visual evidence for these two distinct Fe-based deactivation mechanisms, which have so far been proposed only on the basis of indirect evidence.

