High-temperature solid oxide electrolysis cells (SOECs) offer high energy efficiency and environmental compatibility for CO₂ conversion but currently face the critical challenges of phase instability and coke formation, especially under the strong polarization conditions. In this study, redox phase-stable CeO₂ cathode materials were modified by co-doping with Mn and Ni, enabling the in situ formation of self-assembled and strongly coupled metal Ni/ceria heterostructures and the modification of bulk properties by increasing redox Ce³⁺ active site numbers, Ni exsolution, oxygen defect concentrations, and electrical properties, which consequently effectively enhanced surface reaction kinetics and electrode series conductivity. The optimized Mn–Ni codoped ceria (CMN) exhibited stable electrochemical performance for nearly 140 h at 750 °C with minimal degradation under mild electrolysis conditions. Under strong polarization (2.0 V) condition, SOECs based on the CMN electrode delivered an impressive current density of 3.05 A∙cm⁻² at 800 °C, accompanied by reliable operational stability over the state-of-the-art Ni-based cermet and widely investigated perovskite oxide cathode catalysts. These findings underscore the synergistic benefits of transition metal codoping and in situ heterostructure engineering in enabling high-performance, carbon-tolerant ceria-based electrodes for SOEC operation under both moderate and harsh operating conditions, advancing practical application.

Replacing traditional polymer-based precursors with small molecules is a promising pathway toward facile and controllable preparation of porous carbons but remains a prohibitive challenge because of the high volatility of small molecules. Herein, a simple, general, and controllable method is reported to prepare porous carbons by converting small organic molecules into organic molecular salts followed by pyrolysis. The robust electrostatic force holding organic molecular salts together leads to negligible volatility and thus ensures the formation of carbons under high-temperature pyrolysis. Meanwhile, metal moieties in organic molecular salts can be evolved into in-situ templates or activators during pyrolysis to create nanopores. The modular nature of organic molecular salts allows easy control of the porosity and chemical doping of carbons at a molecular level. The sulfur-doped carbon prepared by the ionic solid strategy can serve as robust support to prepare small-sized intermetallic PtCo catalysts, which exhibit a high mass activity of 1.62 A·mg_Pt⁻¹ in catalyzing oxygen reduction reaction for fuel cell applications.