Metal-organic framework membranes with single-atomic centers for photocatalytic CO2 and O2 reduction

• Published in: Nature communications Vol. 12; no. 1; pp. 2682 - 11
• Main Authors: Hao, Yu-Chen, Chen, Li-Wei, Li, Jiani, Guo, Yu, Su, Xin, Shu, Miao, Zhang, Qinghua, Gao, Wen-Yan, Li, Siwu, Yu, Zi-Long, Gu, Lin, Feng, Xiao, Yin, An-Xiang, Si, Rui, Zhang, Ya-Wen, Wang, Bo, Yan, Chun-Hua
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 11.05.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 140/131; 140/146; 140/58; 147/135; 147/137; 147/143; 639/301/299/890; 639/638/298/921; 639/925/357; Carbon dioxide; Catalysts; Diffusion; Fuels; Gas-liquid-solid reactions; Gas-solid interfaces; Gaseous diffusion; Gases; Humanities and Social Sciences; Hydrogen peroxide; Interfaces; Liquid fuels; Mass transfer; Membranes; Metal-organic frameworks; Metals; multidisciplinary; Permeability; Photocatalysis; Photochemical reactions; Photoreduction; Photosynthesis; Quantum efficiency; Reaction kinetics; Science; Science (multidisciplinary); Selectivity; Sustainable energy
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-021-22991-7

The demand for sustainable energy has motivated the development of artificial photosynthesis. Yet the catalyst and reaction interface designs for directly fixing permanent gases (e.g. CO 2 , O 2 , N 2 ) into liquid fuels are still challenged by slow mass transfer and sluggish catalytic kinetics at the gas-liquid-solid boundary. Here, we report that gas-permeable metal-organic framework (MOF) membranes can modify the electronic structures and catalytic properties of metal single-atoms (SAs) to promote the diffusion, activation, and reduction of gas molecules (e.g. CO 2, O 2 ) and produce liquid fuels under visible light and mild conditions. With Ir SAs as active centers, the defect-engineered MOF (e.g. activated NH 2 -UiO-66) particles can reduce CO 2 to HCOOH with an apparent quantum efficiency (AQE) of 2.51% at 420 nm on the gas-liquid-solid reaction interface. With promoted gas diffusion at the porous gas-solid interfaces, the gas-permeable SA/MOF membranes can directly convert humid CO 2 gas into HCOOH with a near-unity selectivity and a significantly increased AQE of 15.76% at 420 nm. A similar strategy can be applied to the photocatalytic O 2 -to-H 2 O 2 conversions, suggesting the wide applicability of our catalyst and reaction interface designs. Photoreduction of permanent gas faces challenges in reactant diffusion and activation at the three-phase interface. Here the authors showed porous metal-organic framework membranes decorated by metal single atoms can boost the photoreduction of CO 2 and O 2 at the high-throughput gas-solid interface.