V ₂ O ₅ Surface Electronic Structure Suppresses Ethane Over‐Oxidation, Enabling 65% Ethylene Yield

ABSTRACT

Electrochemical oxidative dehydrogenation (ODH) of ethane in solid oxide electrolysis cells (SOECs) offers an energy‐efficient route to ethylene but faces a trade‐off between conversion and selectivity due to over‐oxidation. Conventional voltage–current regulation can suppress deep oxidation but inevitably compromises ethane conversion. Here, we engineer surface electronic structures by depositing a V ₂ O ₅ layer on SrFe _0.9 Ti _0.1 O _3−δ (STF), introducing intrinsic O 2p (‐1.33 eV) and V 3d (‐0.18 eV) states closer to the Fermi level than in STF (‐1.49/‐4.52 eV). Density functional theory and operando infrared spectroscopy reveal three synergistic effects: enhanced ethane adsorption (Δ E _ads ‐0.33 vs. ‐0.11 eV), reduced first dehydrogenation barrier (Δ G ₁ 1.13 vs. 1.15 eV), and promoted ethylene desorption ((Δ G _des ‐Δ G ₃ ) ‐4.98 vs. ‐1.92 eV). The optimized anode delivers 65% yield and 90% selectivity at 750°C, exceeding unmodified STF by 10%. This work highlights band‐center engineering as a promising design concept for regulating hydrocarbon electrode reactions.