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

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 PrBaFe1.6Ni0.2Nb0.2O6‐δ (Pr0.9Ba0.9Li0.2Fe1.6Ni0.2Nb0.2O6‐δ, PBLFNN), inducing the spontaneous formation of surface‐active oxide nanoparticles composed of Fe‐Ni‐O (NixFe1‐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 NixFe1‐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.