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 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.