Spatially confined catalysis-enhanced high-temperature carbon dioxide electrolysis

Abstract

In this study, a potential ilmenite cathode material Ni_0.9TiO₃ is designed for efficient CO₂ electrolysis in an oxide-ion-conducting solid-oxide electrolyzer. Spatially confined catalysis has been successfully achieved to substantially improve cathode activity by in situ growth of catalytically active nickel nanoparticles on a ceramic skeleton. The combined analysis of XRD, SEM, EDS, XPS, TGA and Raman results together confirm that the growth of nickel catalyst is completely reversible in redox cycles. The n-type electrical properties of cathodes are systematically investigated and correlated to electrochemical performance. Efficient CO₂ electrolysis with a Faraday efficiency above 90% has been demonstrated with Ni_0.9TiO₃ in contrast to 60% for a TiO₂ cathode at 800 °C.