Pr and Mo Co‐Doped SrFeO3–δ as an Efficient Cathode for Pure CO2 Reduction Reaction in a Solid Oxide Electrolysis Cell

Abstract

Electroreduction of carbon dioxide (CO2) to carbon monoxide (CO) via a solid oxide electrolysis cell, simplified as CO2RR, is now attracting more and more attention because it can effectively utilize greenhouse gas and efficiently convert surplus electrical energy into chemical energy. In this work, a stable cathode material Pr0.4Sr0.6Fe0.875Mo0.125O3–δ (PSFM), which can be transferred to metallic Fe nanoparticles–structured PSFM (Fe@PSFM) cathode through the in situ exsolution method, has been successfully prepared for CO2RR application, and exhibits a considerable electrolysis current density of 0.71 A cm−2 with good stability when operated at 800 °C and 1.5 V. It is demonstrated that a critical applied voltage is needed for initiating the in situ exsolution of metallic Fe nanoparticles, which can effectively accelerate the CO2 adsorption, dissociation ionization, and surface diffusion to three phase boundaries (TPBs) processes. These results indicate that PSFM is a promising cathode candidate for CO2RR application because of its good electrochemical performance and stability. The findings can guide the development of other ceramic nanostructured electrode decorated with in situ exsolved metallic nanoparticles for energy conversion and storage devices.