Selective Synthesis of Ethane from Methane by a Photocatalytic Chemical Cycle Process

Abstract

Synthesis of value-added chemicals from methane remains a great challenge due to its high energy requirement, low conversion efficiency, and unavoidable over-oxidation of desired products. Here, the integration of a photon-driven chemical cycle process with a continuous flow reactor over the Co0.2Pd1.8-TiO2 catalyst has led to the continuous synthesis of C2H6 from CH4 with ≈100% selectivity under ambient conditions, simultaneously avoiding mixing flammable gas methane with O2 for the chemicals production. Such high selectivity and activity are due to the active lattice oxygen of PdOL and the oxygen-lean condition characterized in the chemical cycle, together with Co single atoms for the regeneration of the photocatalyst surface during the chemical cycle process. The consumed oxygen in PdOL can be compensated by air during the subsequent catalyst regeneration process, leading to the stable activity during a 43 cycles test. Furthermore, this work to some extent demonstrates that the chemical cycle process not only improves the technoeconomic viability but also enhances safety of the process.