Photocatalytic conversion of methane selectively into oxygenated products in the presence of chloride ions

Abstract

Selective partial oxidation of methane to methanol under mild conditions remains a great challenge in activating the first CH bond of CH4 and inhibiting overoxidation. Chlorine-mediated pathway arises as a promising strategy to obtain high CH4 conversion under mild conditions. Herein, a considerable CH3OH production rate of 180.75 μmol·gcat−1·h−1 with 80.07 % selectivity is achieved when the BiOCl with oxygen vacancies is irradiated by visible light in NaCl solution with H2O2 addition. Experimental studies reveal that chlorine radicals are in situ produced and constrained on the surface of the catalyst, which inhibits the over halogenation. Reactive oxygen species produced by H2O2 dissociation were utilized to be the receptors of CH3. The high productivity of methanol was achieved by the synergy effect of chlorine radicals and H2O2. This work provides a new feasible method to convert inert methane into high-value-added products via photocatalysis.