PUBLICATION: NATURE COMMUNICATIONS

AUTHORS: Hao, YC; Chen, LW; Li, JN; Guo, Y; Su, X; Shu, M; Zhang, QH; Gao, WY; Li, SW; Yu, ZL; Gu, L; Feng, X; Yin, AX; Si, R; Zhang, YW; Wang, B; Yan, CH

 

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. CO2, 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. CO2, 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 NH2-UiO-66) particles can reduce CO2 to HCOOH with an apparent quantum efficiency (AQE) of 2.51% at 420nm 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 CO2 gas into HCOOH with a near-unity selectivity and a significantly increased AQE of 15.76% at 420nm. A similar strategy can be applied to the photocatalytic O-2-to-H2O2 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 CO2 and O-2 at the high-throughput gas-solid interface.

 

LINKS: http://dx.doi.org/10.1038/s41467-021-22991-7