Nd-doped Ba(Ce,Zr)O3 − δ proton conductors for application in conversion of CO2 into liquid fuels

► Ba(Ce1 − xZrx)0.9Nd0.1O2.95, x = 0, 0.25, 0.5, 0.75 perovskite-structure materials. ► Transformation of crystal structure upon increasing Zr content. ► The highest proton conductivity for xZr = 0 and 0.25. ► The highest chemical stability in CO2 atmosphere for high-Zr-content materials. ► 2 μm membrane of Ba(Ce0.75Zr0.25)0.9Nd0.1O2.95 successfully prepared.