Boosting Electrocatalytic Ethylene Epoxidation by Single Atom Modulation

An inverse single atom Ru-doped KIr₄O₈ nanowire catalyst, with electronic structures of adjacent Ir sites being modulated by single Ru atoms, is developed for electrocatalytic ethylene epoxidation to ethylene oxide (EO). It achieves an EO partial current density up to 0.7 A cm⁻² and an EO yield as high as 92.0 %.

Abstract

The electrochemical synthesis of ethylene oxide (EO) using ethylene and water under ambient conditions presents a low-carbon alternative to existing industrial production process. Yet, the electrocatalytic ethylene epoxidation route is currently hindered by largely insufficient activity, EO selectivity, and long-term stability. Here we report a single atom Ru-doped hollandite structure KIr₄O₈ (KIrRuO) nanowire catalyst for efficient EO production via a chloride-mediated ethylene epoxidation process. The KIrRuO catalyst exhibits an EO partial current density up to 0.7 A cm⁻² and an EO yield as high as 92.0 %. The impressive electrocatalytic performance towards ethylene epoxidation is ascribed to the modulation of electronic structures of adjacent Ir sites by single Ru atoms, which stabilizes the *CH₂CH₂OH intermediate and facilitates the formation of active Cl₂ species during the generation of 2-chloroethanol, the precursor of EO. This work provides a single atom modulation strategy for improving the reactivity of adjacent metal sites in heterogeneous electrocatalysts.

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