Synergy of Ag and AgBr in a Pressurized Flow Reactor for Selective Photocatalytic Oxidative Coupling of Methane

Chao Wang; Xiyi Li; Yifei Ren; Haimiao Jiao; Feng Ryan Wang; Junwang Tang

doi:10.1021/acscatal.2c06093

Synergy of Ag and AgBr in a Pressurized Flow Reactor for Selective Photocatalytic Oxidative Coupling of Methane

ACS Catal. 2023 Mar 2;13(6):3768-3774. doi: 10.1021/acscatal.2c06093. eCollection 2023 Mar 17.

Authors

Chao Wang¹, Xiyi Li¹, Yifei Ren¹, Haimiao Jiao¹, Feng Ryan Wang¹, Junwang Tang^{1

2}

Affiliations

¹ Department of Chemical Engineering, University College London, London WC1E 7JE, U.K.
² Industrial Catalysis Center, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China.

Abstract

Oxidation of methane into valuable chemicals, such as C₂₊ molecules, has been long sought after but the dilemma between high yield and high selectivity of desired products remains. Herein, methane is upgraded through the photocatalytic oxidative coupling of methane (OCM) over a ternary Ag-AgBr/TiO₂ catalyst in a pressurized flow reactor. The ethane yield of 35.4 μmol/h with a high C₂₊ selectivity of 79% has been obtained under 6 bar pressure. These are much better than most of the previous benchmark performance in photocatalytic OCM processes. These results are attributed to the synergy between Ag and AgBr, where Ag serves as an electron acceptor and promotes the charge transfer and AgBr forms a heterostructure with TiO₂ not only to facilitate charge separation but also to avoid the overoxidation process. This work thus demonstrates an efficient strategy for photocatalytic methane conversion by both the rational design of the catalyst for the high selectivity and reactor engineering for the high conversion.