Selective photocatalytic aerobic oxidation of methane to value-added chemicals offers a promising pathway for sustainable chemical industry,yet remains a huge challenge owing to the consecutive overoxidation of primar...Selective photocatalytic aerobic oxidation of methane to value-added chemicals offers a promising pathway for sustainable chemical industry,yet remains a huge challenge owing to the consecutive overoxidation of primary products.Here,a type II heterojunction were constructed in Ag-AgBr/ZnO to reduce the oxidation potential of stimulated holes and prevent the undesirable CH_(4) overoxidation side reactions.For photocatalytic oxidation of methane under ambient temperature,the products yield of 1499.6μmol gcat^(-1) h^(-1) with a primary products selectivity of 77.9%was achieved over Ag-AgBr/ZnO,which demonstrate remarkable improvement compared to Ag/ZnO(1089.9μmol gcat^(-1) h^(-1) ,40.1%).The superior activity and selectivity result from the promoted charge separation and the redox potential matching with methane activation after introducing AgBr species.Mechanism investigation elucidated that the photo-generated holes transferred from the valence band of ZnO to that of AgBr,which prevent H_(2)O oxidation and enhance the selective generation of•OOH radical.展开更多
基金supported by the National Natural Science Foundation of China(22208290,22288102,22078288,22225802)the key R&D Program Projects in Zhejiang Province(2021C03005).
文摘Selective photocatalytic aerobic oxidation of methane to value-added chemicals offers a promising pathway for sustainable chemical industry,yet remains a huge challenge owing to the consecutive overoxidation of primary products.Here,a type II heterojunction were constructed in Ag-AgBr/ZnO to reduce the oxidation potential of stimulated holes and prevent the undesirable CH_(4) overoxidation side reactions.For photocatalytic oxidation of methane under ambient temperature,the products yield of 1499.6μmol gcat^(-1) h^(-1) with a primary products selectivity of 77.9%was achieved over Ag-AgBr/ZnO,which demonstrate remarkable improvement compared to Ag/ZnO(1089.9μmol gcat^(-1) h^(-1) ,40.1%).The superior activity and selectivity result from the promoted charge separation and the redox potential matching with methane activation after introducing AgBr species.Mechanism investigation elucidated that the photo-generated holes transferred from the valence band of ZnO to that of AgBr,which prevent H_(2)O oxidation and enhance the selective generation of•OOH radical.
