Proton ceramic electrochemical cells offer the opportunity to intensify hydrocarbon conversion processes by in-situ H₂ extraction. However, the non-oxidative operating conditions are prone to produce coke, resulting in catalyst deactivation and loss of electrode performance. To remove such coke, an oxidative regeneration cycle and electrodes stable under redox conditions are necessary. Current research on stable electrodes under redox conditions is based on materials such as Mn-doped LaCrO₃ perovskites, which exhibit high electronic conductivity and good stability in reducing atmospheres.
The main objective of this work is the development and electrochemical characterisation of different material candidates as redox-stable electrodes for its integration into proton ceramic cells, which allows operation under both non-oxidative H₂ removal and coke oxidation conditions. Composite materials, based on BaCe_0.2Zr_0.7Y_0.1O_3-δ (BCZY₂₇) as protonic phase and La_0.85Sr_0.15FeO₃ (LSF₈₅₁₅), La_0.5Sr_0.5FeO₃ (LSF₅₅), La_0.84Sr_0.16Cr_0.5Mn_0.5O₃ (LSCM) or La_0.8Sr_0.2MnO₃ (LSM) as electronic phase are investigated. An alternative method to optimize the electrode is also suggested by catalytically activating the electrode surface with Pt and CeO₂ nanoparticles. Chemical and structural compatibility, electrochemical impedance spectroscopy and stability under redox cycling in the range of 500-800 °C will be discussed. In addition, coke formation of LSCM and LSM powders in CH₄ and aromatic atmospheres are investigated. This study demonstrates that LSCM and LSM electrodes have high potential for non-oxidative hydrocarbon upgrading and redox-regenerative cycling. Moreover, further optimization of the electronic phase is being carried out.
 
Acknowledgements:
The work leading to these results has received funding from Spanish Government (RTI2018-102161 grant) and has been supported by the WINNER project. This project has received funding from the Fuel Cells and Hydrogen 2 Joint Undertaking (now Clean Hydrogen Partnership) under Grant Agreement No 101007165. This Joint Undertaking receives support from the European Union's Horizon 2020 Research and Innovation program, Hydrogen Europe and Hydrogen Europe Research.