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

Abstract Selective conversion of ethane (C 2 H 6 ) 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 ‐C 4 H 10 ) by using CO 2 as an oxidant. Remarkably, the as‐prepared NiTi‐LDH exhibits a high selectivity for n ‐C 4 H 10 (92.35%) with a production rate of 62.06 µmol g −1 h −1 when the feed gas (CO 2 /C 2 H 6 ) 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 C 2 H 6 to n ‐C 4 H 10 . 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 C 2 H 4 or CH 4 , resulting in the high production rate and selectivity for n ‐C 4 H 10 .