Volatilization‐Induced Local Formation of Surface‐Active Nanoparticles for Efficient Electrochemical Reduction of Pure CO₂

Abstract Efficient CO₂ electroreduction is an enabling technology for zero CO₂ emission in many novel electrochemical fossil fuel utilization technologies, such as direct coal fuel cells. Solid oxide electrolysis cells (SOECs) offer the highest potential for large‐scale CO₂ electroreduction due to the higher current density and energy efficiency compared to low‐temperature CO₂ electrolysis. However, conventional unmodified cathodes suffer from low activity and rapid degradation in pure CO₂ at high temperatures. Here, a material design strategy is demonstrated that enhances perovskite cathode activity and stability by doping Li into PrBaFe_1.6Ni_0.2Nb_0.2O_6‐δ (Pr_0.9Ba_0.9Li_0.2Fe_1.6Ni_0.2Nb_0.2O_6‐δ, PBLFNN), inducing the spontaneous formation of surface‐active oxide nanoparticles composed of Fe‐Ni‐O (Ni_xFe_1‐xO) via Li₂O volatilization during synthesis, without the need for additional modification. The PBLFNN‐SDC cathode achieved a high current density of 1.76 A cm⁻² at 1.5 V and 800 °C in pure CO₂, a 74.26% improvement over the undoped PBFNN‐SDC cathode. DFT calculations confirmed that Li doping and Ni_xFe_1‐xO exsolution synergistically lower the oxygen vacancy formation energy and promote CO₂ adsorption and activation. This findings introduce a scalable, non‐external modification exsolution strategy for designing high‐performance perovskite‐based cathodes for more efficient and durable CO₂ electroreduction.