Grain-Boundary-Engineered La₂CuO₄Perovskite Nanobamboos for Efficient CO₂Reduction Reaction

Electroreduction of carbon dioxide (CO2RR) has been regarded as a promising approach to realize the production of useful fuels and to decrease greenhouse gas levels simultaneously, where high-efficiency catalysts are required. Herein, we report La2CuO4 nanobamboo (La2CuO4 NBs) perovskite with rich twin boundaries showing a high Faraday efficiency (FE) of 60% toward ethylene (C2H4), whereas bulk La2CuO4 exhibits a FECO of 91%. X-ray absorption spectroscopy (XAS) reveals that the Cu in La2CuO4 NBs is in the Cu2+ state, and no obvious change can be observed during the catalytic process, as monitored by in situ XAS. Density functional theory calculations reveal that the superior FEC2H4 of La2CuO4 NBs originates from the active (113) surfaces with intrinsic strain. The formation of gap states annihilates the electron transfer barrier of C-C coupling, resulting in the high FEC2H4. This work provides a new perspective for developing efficient perovskite catalysts via grain boundary engineering.