Self-Assembled Controllable Cu-Based Perovskite/Calcium Oxide Hybrids with Strong Interfacial Interactions for...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Copper-based perovskite oxides are promising for CO2 electromethanation but face challenges with methane selectivity and catalyst stability.
• Developing advanced catalysts with improved performance is critical for efficient electrochemical conversion of CO2 into valuable products like methane.

Purpose of the Study:

• To design and synthesize self-assembled Cu-based perovskite/calcium oxide hybrids with controlled interfacial interactions for enhanced CO2 electromethanation.
• To investigate the relationship between interfacial properties, catalyst structure, and performance in methane electrosynthesis.

Main Methods:

• Fabrication of a series of La2CuO4/(CaO)x catalysts with varying CaO concentrations (x = 0.2–1.2).
• Characterization of catalyst structure, phase composition, and interfacial properties using experimental and theoretical methods.
• Electrochemical testing of catalysts for CO2 reduction to CH4, evaluating activity, selectivity, and stability.

Main Results:

• The synthesized La2CuO4/(CaO)x hybrids exhibit strong interfacial interactions due to electron transfer from Ca2+ to Cu2+.
• Catalyst performance, including activity and CH4 selectivity, showed a volcano-type dependence on CaO concentration and correlated positively with interface size.
• The optimal catalyst, La2CuO4/(CaO)0.8, achieved a high CH4 selectivity of 77.6% at 300 mA cm-2 with good stability, outperforming physical mixtures and many existing Cu-based perovskites.

Conclusions:

• Self-assembly-induced strong interfacial interactions in Cu-based perovskite/calcium oxide hybrids are key to enhancing CO adsorption/hydrogenation and improving catalyst stability.
• These findings demonstrate a promising strategy for designing high-performance catalysts for efficient and selective CO2 electrosynthesis into methane.