Role of Copper Migration in Nanoscale Ageing of Supported CuO/Al ₂ O ₃ in Redox Conditions: A Combined Multiscale X‐ray and Electron Microscopy Study

Chemical Looping Combustion is a promising midterm solution to mitigate CO2 emission, by carrying out indirect fuel combustion and allowing inherent separation of CO2. During the CLC process, an oxygen material subjected successive oxidation-reduction reactions at high temperature which induce significant degradation. CuO/Al2O3 based materials have been widely considered as carriers (OC). However, carrier ageing mechanisms (active phase migration interactions with support, transitions) are not well understood. Herein, in-depth overview evolution achieved employing multi-scale characterization approach. At μm-scale, copper within alumina support has observed using Scanning Transmission X-ray Microscopy (STXM) Electron (SEM). The spatial distribution Cu−Al species provides information on mobility different phases interactions. A comprehensive mechanism proposed concerning redox behaviour system, relating diffusion Cu-species, active phase-support interactions, role in Al2O3 transition number cycles. Understanding process paves way design more stable oxygen-carriers.