Highly selective oxidation of methane to formaldehyde on tungsten trioxide by lattice oxygen
Yingying Fan, Peiyun Zhang, Rongxia Lu, Yuheng Jiang, Guoliang Pan, Wei Wang, Xianglian Zhu, Shilei Wei, Dongxue Han, Li Niu
Abstract
Photocatalytic oxidation of methane into formaldehyde in high yield and selectivity remains a grand challenge due to the ineluctable intermediates. Here, we report that a {001}, {010} and {100} facets modified tungsten trioxide photocatalyst enables an intermediate-free oxidation of methane into formaldehyde with 99.4% selectivity. A durable formaldehyde yield of 4.61 mmol g−1 can be achieved after irradiation for 30 h. Mechanism studies disclose that surface defect and reactive lattice oxygen atom are crucial for the selectivity and productivity promotion. This work provides a valid paradigm for efficient conversion of methane to formaldehyde.