Composite Cathode Based on Redox‐Reversible NbTi0.5Ni0.5O4 Decorated with In Situ Grown Ni Particles for Direct Carbon Dioxide Electrolysis

In this work, ceramic NbTi0.5Ni0.5O4 is reversibly transformed to nickel‐anchored electronic‐conducting Nb1.33Ti0.67O4 composite for the use of direct carbon dioxide electrolysis at intermediate temperatures. The reduced composites Nb1.33Ti0.67O4 + Ni demonstrate excellent electrical properties, which have been accordingly correlated to electrochemical performance of the composite cathode. The direct electrolysis of 100% CO2 is then performed and the maximum Faraday current efficiency reaches as high as 65%. It is found that adding 3% H2O to CO2 remarkably improves the electrolysis performances and the current efficiency is accordingly enhanced by approximately 20%. The reversible transformation between NbTi0.5Ni0.5O4 and Nb1.33Ti0.67O4 + Ni sample significantly contributes to the promising thermal and redox cycling performance while the anchored interface between Ni and Nb1.33Ti0.67O4 improves cathode stability.