Metal nanoparticles at grain boundaries of titanate toward efficient carbon dioxide electrolysis

Abstract

The surface reaction kinetics of perovskite oxides is usually regulated by the formation of carriers in the crystal lattice by element doping, but there are few studies on improving the surface exchange coefficient by adjusting the microstructure. In this work, a significant increase in the titanate surface exchange coefficient was achieved by in situ growth of active nickel nanoparticles at grain boundaries by controlling the nonstoichiometry of the oxide material. Chemically customized titanates lead to a significant improvement in electrochemical performance. A current density of 1.28 A cm⁻² was obtained by direct electrolysis of carbon dioxide at 1.8 V and 800 °C. The concepts exemplified here can be used to design and develop more complex oxide materials with advanced capabilities across a range of possible application areas.