Enhancing CO2 electrolysis performance in solid oxide electrolysis cell using La-doped SrTiO3-δ composites
Xiaoyong Xu, Han Xu, Haobo Li, Abel Santos, Jie Zhao, Shintaro Idab
Abstract
Electrochemically reducing carbon dioxide by solid oxide electrolysis cells (SOECs) is a promising approach to minimize greenhouse gas emissions and generate high added value chemicals and fuels using renewable energy. However, the practical use of CO 2 electrolysis in SOECs faces challenges because of the scarcity of effective and stable cathode materials. This study explores La-doped SrTiO 3-δ composites as cathode materials for CO 2 electrolysis. By judiciously adjusting the La/Sr ratio, the perovskite structure's oxygen vacancies, lattice oxygen formation, and the content of Sr on the surface, a high CO 2 reduction activity is achieved. These adjustments enhance CO 2 adsorption and dissociation, leading to an improvement of catalytic activity and operational stability. La 0.4 Sr 0.5 TiO 3-δ shows a significantly enhanced CO 2 electrolysis performance with a high Faraday efficiency, a current density of 0.64 A cm −2 at 850 °C and over 140 h of stability. The evaluation of various La-doped SrTiO 3-δ composites highlights their potential as efficient cathode materials for CO 2 electrolysis in SOECs. • Engineering Surface Oxophilicity for CO 2 Electrolysis was achieved by adjusting the La/Sr ratio. • Enhancing CO 2 adsorption and dissociation improves catalytic activity and stability. • LST45 exhibits the highest CO 2 electrolysis performance at 850 °C. • LST45 exhibits a long-term stability, no obvious degradation in 140 h.