Photocatalytic Dry Reforming of Methane Enhanced by "Dual-Path" Strategy with Excellent Low-Temperature Catalytic Performance

Dry reforming of methane (DRM), which involves the activation of inert C-H bonds and C(sic)O bonds, at mild conditions is a tremendous challenge. The sluggish mobility of oxygen during the reaction is known as a key issue causing low activity and poor stability of catalysts by the coke formation. Herein, a novel Cu-CNN/Pd-BDCNN photocatalyst that is made up of "Cu-nanoparticle-loaded g-C3N4 nanosheets" and "Pd-nanoparticle-loaded boron-doped nitrogen-deficient g-C3N4 nanosheets" is reported. The existing dual-reaction-sites benefit the reactive oxygen intermediates participate in the reaction directly without distant migration. The in situ characterizations and density functional theory calculations reveal a newly dual reaction pathway through simultaneous dehydrogenation of methoxy and methyl intermediates, and demonstrate the importance of metal loading, which promote the CO2 and CH4 activation from both aspects of thermodynamics and kinetics. The optimized Cu-CNN/Pd-BDCNN photocatalyst displays an excellent syngas formation rate of over 800 mu mol g(-1) h(-1) with H-2/CO = 1 and splendid stability in continuous flow reaction under 300 mW cm(-2) xenon lamp irradiation at room temperature. The "dual-site" and "dual-path" strategy shed light on the design of effective photocatalysts for methane dry reforming.