Phase Transition Engineering of Host Perovskite toward Optimal Exsolution‐facilitated Catalysts for Carbon Dioxide Electrolysis

The in situ exsolution technique of nanoparticles has brought new opportunities for the utilization of perovskite‐based catalysts in solid oxide cells. However, the lack of control over the structural evolution of host perovskites during the promotion of exsolution has restricted the architectural exploitation of exsolution‐facilitated perovskites. In this study, we strategically broke the long‐standing trade‐off phenomenon between promoted exsolution and suppressed phase transition via B‐site supplement, thus broadening the scope of exsolution‐facilitated perovskite materials. Using carbon dioxide electrolysis as an illustrative case study, we demonstrate that the catalytic activity and stability of perovskites with exsolved nanoparticles (P‐eNs) can be selectively enhanced by regulating the explicit phase of host perovskites, accentuating the critical role of the architectures of perovskite scaffold in catalytic reactions occurring on P‐eNs. The concept demonstrated could potentially pave the way for designing the advanced exsolution‐facilitated P‐eNs materials and unveiling a wide range of catalytic chemistry taking place on P‐eNs. We have implemented a set of strategies to precisely control the phase evolution of host perovskite without compromising exsolution. Using carbon dioxide electrolysis as an example, we demonstrated how regulating phase structure can enhance the activity and stability of exsolved perovskites, emphasizing the importance of phase evolution control in catalytic chemistry occurring on perovskites with exsolution.