Photocatalytic Oxidative Coupling of Ethane to n‐Butane Using CO₂ as a Soft Oxidant over NiTi‐Layered Double Hydroxide

Abstract Selective conversion of ethane (C₂H₆) to high‐value‐added chemicals is a very important chemical process, yet it remains challenging owing to the difficulty of ethane activation. Here, a NiTi‐layered double hydroxide (NiTi‐LDH) photocatalyst is reported for oxidative coupling of ethane to n‐butane (n‐C₄H₁₀) by using CO₂ as an oxidant. Remarkably, the as‐prepared NiTi‐LDH exhibits a high selectivity for n‐C₄H₁₀ (92.35%) with a production rate of 62.06 µmol g⁻¹ h⁻¹ when the feed gas (CO₂/C₂H₆) ratio is 2:8. The X‐ray absorption fine structure (XAFS) and photoelectron characterizations demonstrate that NiTi‐LDH possesses rich vacancies and high electron–hole separation efficiency, which can promote the coupling of C₂H₆ to n‐C₄H₁₀. More importantly, density functional theory (DFT) calculations reveal that ethane is first activated on the oxygen vacancies of the catalyst surface, and the C─C coupling pathway is more favorable than the C─H cleavage to C₂H₄ or CH₄, resulting in the high production rate and selectivity for n‐C₄H₁₀.