Stable, High-Yield Ethylene Production from Vapor-Assisted Light-Driven Ethane Dehydrogenation

Ethane (C₂H₆) dehydrogenation (EDH) is a core industrial process for on-purpose ethylene production but is severely constrained by thermodynamics and typically requires elevated temperatures (>600 °C). Light-driven EDH (LDEDH) offers a sustainable alternative by harvesting solar energy to produce ethylene (C₂H₄) under mild conditions, yet its development has been hindered by low C₂H₄ productivity and poor operational stability (typically <12 h). Here, we realize a vapor-assisted LDEDH process in a continuous-flow reactor over Pd nanoclusters supported on an interface-engineered ZnO-TiO₂ heterojunction in which a conformal TiO₂ overlayer on ZnO constructs a lattice-preserving Ti-O-Zn interface that maximizes the interfacial area and enables directional charge separation tailored for oxidative EDH. Mechanistic studies reveal that this strong interfacial synergy drives photogenerated electrons to ZnO and holes to the TiO₂ overlayer while Pd nanoclusters promote electron transfer and enhance C₂H₆ adsorption. As a result, Pd/ZnO-TiO₂ achieves a record-high C₂H₄ productivity of 1640.9 μmol h^-1 with a selectivity of 98.7%, surpassing the current state of the art by more than 7-fold and setting a new benchmark for LDEDH. In addition, the presence of water vapor not only supplies ·OH species for LDEDH but also can suppress coke deposition, which enables superior long-term stability for 152 h, largely surpassing that of the reported catalysts (typically below 12 h).