While plasma catalysis enables CO2 hydrogenation under mild conditions, catalyst activation still commonly relies on conventional high-temperature thermal pretreatments, which interrupt continuous operation and limit the practical integration of plasma catalysis with intermittent renewable energy systems. In this study, plasma activation and thermal activation were compared for the plasma-catalytic reverse water-gas shift (RWGS) reaction using La2CuO4 as a precursor. Plasma-activated La2CuO4 exhibited significantly enhanced CO2 conversion compared with its thermally activated counterpart. Comprehensive structural and spectroscopic analyses, including Cu LMM Auger spectroscopy, Cu K-edge XANES, and XPS, revealed that mild plasma irradiation induced surface reconstruction, forming a Cu+-enriched and oxygen-defective surface while largely preserving the La2CuO4 framework. La-involved electronic interactions and oxygen-vacancy-related reconstruction of the local Cu−O coordination environment jointly contributed to the formation and stabilization of Cu+ species. CO2-TPD and WO3-assisted H2 spillover experiments further suggested that the plasma-induced Cu+-enriched surface promoted more balanced CO2 adsorption/activation and H2 activation/migration, thereby contributing to efficient plasma-RWGS performance. This work offers a plasma-oriented route for in situ catalyst activation and surface-state regulation in plasma-catalytic CO2 hydrogenation.
