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

Abstract Efficient CO 2 electroreduction is an enabling technology for zero CO 2 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 CO 2 electroreduction due to the higher current density and energy efficiency compared to low‐temperature CO 2 electrolysis. However, conventional unmodified cathodes suffer from low activity and rapid degradation in pure CO 2 at high temperatures. Here, a material design strategy is demonstrated that enhances perovskite cathode activity and stability by doping Li into PrBaFe 1.6 Ni 0.2 Nb 0.2 O 6‐δ (Pr 0.9 Ba 0.9 Li 0.2 Fe 1.6 Ni 0.2 Nb 0.2 O 6‐δ , PBLFNN), inducing the spontaneous formation of surface‐active oxide nanoparticles composed of Fe‐Ni‐O (Ni x Fe 1‐x O) via Li 2 O 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 CO 2 , a 74.26% improvement over the undoped PBFNN‐SDC cathode. DFT calculations confirmed that Li doping and Ni x Fe 1‐x O exsolution synergistically lower the oxygen vacancy formation energy and promote CO 2 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 CO 2 electroreduction.