Cation-Deficiency-Dependent CO₂ Electroreduction over Copper-Based Ruddlesden-Popper Perovskite Oxides

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Copper-based perovskite oxides are promising catalysts for CO2 electroreduction (CER).
• Tailoring their properties is crucial for efficient CER.
• A-site cation deficiency is an underexplored strategy for property enhancement.

Purpose of the Study:

• To investigate the effect of A-site cation deficiency on the CER performance of Cu-based Ruddlesden-Popper (RP) perovskite oxides.
• To optimize catalysts for selective production of C2+ or methane (CH4).
• To elucidate the structure-property relationships governing CER.

Main Methods:

• Synthesis of La2-xC (x=0, 0.1, 0.2, 0.3) perovskite oxides.
• Electrochemical characterization of CER activity and selectivity.
• Analysis of the influence of cation deficiency on oxygen vacancies and surface properties.

Main Results:

• CER activity and selectivity exhibited volcano-type or inverted volcano-type dependence on A-site deficiency (x).
• La1.9C demonstrated optimal C2+ production (51.3 mA cm-2, 41.5%) at -1.4 V.
• La1.7C showed the best CH4 production (25.1 mA cm-2, 22.1%).

Conclusions:

• A-site cation deficiency is an effective strategy to enhance CER performance in Cu-based RP oxides.
• Optimized catalysts exhibit competitive activity and selectivity for C2+ and CH4.
• Cation-deficiency-induced oxygen vacancies and CuO/RP hybrids facilitate reaction pathways.