Synergistic Bifunctionality of Interfacial Pd–Ov Sites on ZnO for Highly Selective Photocatalytic Ethane Dehydrogenation

Photocatalytic oxidative dehydrogenation of ethane (ODHE) is a promising route to ethylene under mild conditions, yet achieving a high yield and selectivity is challenging due to the inert C–H bonds and overoxidation to CO2. In this study, we present ZnO fine nanoparticles decorated with highly dispersed Pd species and featuring closely associated interfacial oxygen vacancies (Ov) for highly selective ODHE. The optimized catalyst achieves a C2H4 production rate of 8.5 mmol g–1 h–1 with a selectivity of up to 96.1%, surpassing most reported photo- and thermocatalysts and maintaining robust stability for over 10 h. Through a combination of operando DRIFTS, in situ XPS, and in situ EPR analyses, we demonstrate that the enhanced photocatalytic performance stems from a synergistic, spatially separated dual-site configuration involving Pd species and adjacent interfacial Ov. This configuration enhances spatial charge separation, promotes oxygen activation, and facilitates the selective conversion of C2H6 into key *C2H4 intermediates, thereby boosting ethylene formation. This work not only provides fundamental insights into the photocatalytic ODHE mechanism but also underscores the importance of interfacial engineering in the design of highly efficient photocatalysts for alkane conversion.