Selective Production of Acetylene from the C─C Coupling Reaction of CH ₄ with CO ₂ Mediated by Ta ₂ O ₂ ⁺ Cluster Cations

Abstract Coconversion of methane and carbon dioxide to C 2 hydrocarbons via the C CH4 ─C CO2 coupling reaction is of great significance to mitigate greenhouse effect and develop an alternative route for manufacture of important industrial feedstocks (e.g., C 2 H 2 ), however, it has not yet been achieved so far owing to the difficulty in breaking both of the C═O bonds in CO 2 as well as the precise control of sequential elementary reactions targeted for C 2 hydrocarbons. Herein, by using the tantalum oxide Ta 2 O 2 + as an active cluster, an unprecedented C CH4 ─C CO2 coupling reaction of CH 4 with CO 2 to exclusively produce the C 2 hydrocarbon of C 2 H 2 has been successfully realized even at room temperature by the state‐of‐the‐art mass spectrometry. The in situ reconstruction from Ta─O─Ta cluster skeleton to tantalum carbide Ta─C─Ta experienced upon the prereaction with CH 4 is critical to delicately control the sequential elementary reactions targeted for C 2 H 2 generation. This finding not only leads to a breakthrough in the field of gas‐phase and condensed‐phase chemistry wherein the C 2+ oxygenated compounds were the mainstream products for C CH4 ─C CO2 coupling of CH 4 with CO 2 , but also explores a new active structure and a novel reaction mechanism beneficial for selective production of C 2 hydrocarbons from coconversion of CH 4 and CO 2 .