Construction of a metal–oxide interface through alloy nanoparticles to enhance CO2 electrolysis

Abstract

Solid oxide electrolytic cells (SOECs) are widely used in energy conversion and storage technology. However, the traditional cermet material as the cathode is easily oxidized, which greatly reduces the electrolytic performance and efficiency. In this research work, we produce a range of A-site saturated B-site overdoped La_0.7Sr_0.3Cr_0.5Mn_0.5(FeCo)_xO_3−δ(LSCM(FeCo)_x) samples through liquid-phase synthesis. Through the reduction pretreatment of the LSCM(FeCo)_x sample, FeCo alloys are separated from the substrate in the form of alloy nanoparticles and anchored to the substrate to construct the metal–oxide interface and increase the active site. Compared to metal nanoparticles, the size effect of alloy nanoparticles can effectively improve the thermal stability and oxidation resistance of materials and enhance their high-temperature durability. Simultaneously, the three-phase interface consisting of the electrode, the electrolyte, and the gas is increased. The coupling of the metal–oxide interface and the three-phase interface enhances the catalytic activity. At 1.6 V and 850 °C, the electrode LSCM(FeCo)_0.075 resulted in a Faraday current efficiency close to 100% and a yield of 5.03 ml min⁻¹ cm⁻² of CO, about 2.5 times as much as conventional LSCM electrodes. After 100 h of high-temperature testing, the electrochemical performance is stable, which indicates that the construction of the metal–oxide active interfaces and three-phase interfaces could improve the electrocatalytic performance and durability of the material. This research result can provide a reference for the design of efficient and stable catalysts for high-temperature energy and environmental devices.