Light-Induced Redox Looping of a Rhodium/Cex WO3 Photocatalyst for Highly Active and Robust Dry Reforming of Methane.

Abstract

Dry reforming of methane (DRM) has provided an effective avenue to convert two greenhouse gases, CH4 and CO2 , into syngas. Here, we design a DRM photocatalyst Rh/Cex WO3 that invokes both photothermal and photoelectric processes, which overcomes the thermodynamic limitation of DRM under conventional conditions. In contrast to plasmonic or UV-response photocatalysts, our photocatalyst produces a superior light-to-chemical energy efficiency (LTCEE) of 4.65 % with a moderate light intensity. We propose that a light-induced metal-to-metal charge transfer plays a crucial role in the DRM reaction, which induces a redox looping between Ce to W species to lower the activation energy. Quantum mechanical studies reveal that a high oxygen mobility of Cex WO3 , accompanied with the formation of oxo-bridge species, results in a substantial elimination of deposited C species during the reaction. Our catalyst design strategy could offer a promising energy-efficient industrial process for DRM.