Sulfone-Decorated Conjugated Organic Polymers Activate Oxygen for Photocatalytic Methane Conversion.

Oxidizing CH 4 into liquid products with O 2 under mild conditions still mainly relies on metal catalysis. We prepared a series of sulfone-modified conjugated organic polymers and found that the catalyst with proper S VI content (0.10) could drive O 2 →H 2 O 2 →⋅OH to oxidize CH 4 into CH 3 OH and HCOOH directly and efficiently at room temperature under light irradiation. Experimental results showed that after 4 h reaction, decomposition rate and residual amounts of H 2 O 2 were 81.21 % and 4.83 mmol g cat -1 respectively, and CH 4 conversion rate was 22.81 %. Mechanism studies revealed that illumination could induce the homolytic dissociation of S=O bonds on catalyst to produce oxygen and sulfur radicals, where the ⋅O could adsorb and activate CH 4 , and the ⋅S could supply electrons for 1 O 2 to generate H 2 O 2 and then for decomposing the H 2 O 2 into ⋅OH timely to oxidize CH 4 . This research provided a novel organic catalysis approach for oxygen activation and utilization.