Electrified Acetylene Removal From Ethylene Streams Enabled by Facet-Engineered Cu-TiO2 Interfaces.

Removal of trace acetylene from ethylene is essential for polymer-grade olefin production, yet current thermocatalytic purification requires elevated temperatures and hydrogen input. Here we report an electrified route for acetylene removal from ethylene streams using facet-engineered Cu-TiO2 interfaces. By tuning the exposed facets of anatase TiO2, we regulate the interfacial electronic interaction with supported Cu nanoclusters and thereby the balance among acetylene hydrogenation, hydrogen evolution, and carbon-carbon coupling. Among the catalysts examined, Cu-TiO2 {001} provides the most effective interfacial environment for selective acetylene-to-ethylene conversion, delivering an ethylene Faradaic efficiency (FE) of 95.4% under acetylene-rich feed. Under purification-relevant acetylene-lean conditions, a 25 cm2 flow electrode suppresses residual acetylene to below 5 ppm while maintaining H2 FE below 5% during prolonged operation. Combined spectroscopy and theory indicate that the {001} facet strengthens Cu-TiO2 electronic coupling, stabilizes the Cu electronic structure and key hydrogenation intermediates under operating conditions, and disfavors competing pathways. Techno-economic analysis supports the process potential of this electrified purification strategy.