Surfacial proton conducting CeO₂ nanosheets

Proton conducting ceramic fuel cells (PCFCs) have been attracting much more attentions due to is affordable ionic conductivity lower operating temperatures (<600 °C). CeO₂ nanosheets expose mainly to the (111) plane exhibit a super proton conductivity of 0.3 S cm⁻¹ and a maximum power density of 948 mWcm⁻² at 550 °C. In these two morphologies of CeO₂, the difference in Ce³⁺/Ce⁴⁺ ratios and the formation of oxygen vacancies on the surface are mainly responsible for proton transport. Theoretical calculation proves that protons can move more easily on the CeO₂ (111) facet with smaller binding energy (0.14 eV) and lower energy barrier for H–O formation (1.7 eV) than on other facets, also superior proton conduction for the nanosheet morphology over the nano-particles. This work has developed a morphological methodology for high proton surface conduction to design highly efficient ionic transport for advanced CFCs and electrochemical devices.