An extensive exploitation of renewable energies is required to face climate change, and reduce the dependence on fossil fuels. Thermochemical energy storage (TCES) systems are bound to play a major role in the next years to overcome the intrinsic variability of many renewable sources, thus increasing their dispatchability. Within this field, reversible gas-solid chemical reactions are among the most promising systems thanks to high theoretical values of energy storage density, and virtual unlimited time scales of energy storage. Copper oxide is an interesting candidate for TCES, but suffers from particle sintering/agglomeration at the high process temperature required by the system. In this work, several Cu:Ce mixed oxides have been synthesized and tested in a thermogravimetric analyzer under process parameters relevant to TCES applications, with the aim of preventing copper oxide sintering/agglomeration. Morphology and chemical composition of the synthesized and reacted samples have been scrutinized by means of XRD and SEM-EDS analyses.