Titania-supported Cu Single Atom Catalyst for Electrochemical Reduction of Acetylene to Ethylene at Low-Concentrations with Suppressed Hydrogen Evolution.

Electrochemical acetylene reduction (EAR) is a promising strategy for removing acetylene from ethylene-rich gas streams. However, suppressing the undesirable hydrogen evolution is vital for practical applications in acetylene-insufficient conditions. Herein, we immobilized Cu single atoms on anatase TiO 2 nanoplates (Cu-SA/TiO 2 ) for electrochemical acetylene reduction, achieving an ethylene selectivity of ∼97% with a 5 vol.% acetylene gas feed (Ar balance). At the optimal Cu single atom loading, Cu-SA/TiO 2 was able to effectively suppress HER and ethylene over-hydrogenation even when using dilute acetylene (0.5 vol.%) or ethylene-rich gas feeds, delivering a 99.8% acetylene conversion, providing a turnover frequency of 8.9 × 10 -2 s -1 , which is superior to other EAR catalysts reported to date. Theoretical calculations showed that the Cu single atoms and the TiO 2 support acted cooperatively to promote charge transfer to adsorbed acetylene molecules, whilst also inhibiting hydrogen generation in alkali environments, thus allowing selective ethylene production with negligible hydrogen evolution at low acetylene concentrations. This article is protected by copyright. All rights reserved.