In situ plasma-activated La2CuO4 with Cu+-enriched surfaces for efficient plasma-catalytic reverse water−gas shift reaction

Plasma activation improves the plasma-RWGS performance of La 2 CuO 4 . • Plasma activation reconstructs La 2 CuO 4 into a Cu + -enriched surface. • La-mediated electronic interactions and OVs stabilize surface Cu + species. • Cu + -enriched surface promotes coupled CO 2 and H 2 activation. While plasma catalysis enables CO 2 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 La 2 CuO 4 as a precursor. Plasma-activated La 2 CuO 4 exhibited significantly enhanced CO 2 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 La 2 CuO 4 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. CO 2 -TPD and WO 3 -assisted H 2 spillover experiments further suggested that the plasma-induced Cu + -enriched surface promoted more balanced CO 2 adsorption/activation and H 2 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 CO 2 hydrogenation. Download: Download high-res image (183KB) Download: Download full-size image