Probing metal/high-entropy perovskite heterointerfaces for efficient and sustainable CO2 electroreduction

Abstract

Solid oxide electrolysis cells (SOECs) are increasingly recognized for their great potential in the carbon dioxide reduction reaction (CO₂RR). However, the sluggish kinetics of the CO₂RR impedes their widespread commercialization. Here, a novel in situ formed metal/high-entropy perovskite heterointerface, NiFe@Sr₂Fe_0.4V_0.4Mo_0.4Ni_0.4Ti_0.6O_6−δ (SFVMNT), is proposed to enhance the CO₂RR. The electronic conductivity of NiFe@SFVMNT is one order of magnitude higher than that of Sr₂FeMoO_6−δ perovskite. Theoretical analyses reveal that the strong metal/perovskite interaction significantly accelerates CO₂RR kinetics. Moreover, NiFe@SFVMNT with its high-entropy configuration and embedded exsolution structure ensures high stability during the continuous CO₂RR. As an application, the NiFe@SFVMNT-based SOECs demonstrate an impressive current density of 1.66 A cm⁻² at 1.5 V and 800 °C, maintaining nearly consistent performance over 200 h, thereby surpassing most state-of-the-art cathode materials for the CO₂RR. Consequently, this metal/high-entropy perovskite interface emerges as a highly efficient and durable cathode of SOECs towards the CO₂RR.