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

Abstract

AbstractSelective 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.