Filling metal–organic framework mesopores with TiO2 for CO2 photoreduction

Blocked pores shine in CO2 conversion

30 April 2021

Filling some of the nanoscale pores of metal–organic framework (MOF) materials with light-absorbing titanium dioxide particles can significantly boost the MOF’s photocatalytic capabilities.

MOFs’ highly porous structures potentially make them ideal for the uptake and catalysis of small molecules, such as the absorption and photocatalytic reduction of CO₂ into CO and CH₄ (methane). However, MOFs are usually far less efficient than solid-state or molecular catalysts for CO₂ photoreduction.

Now, a team that included ShanghaiTech University scientists has developed a more efficient MOF photoreduction catalyst by exploiting the three different pore sizes found within a chromium-based MOF.

Titanium dioxide particles selectively grew in the MOF’s two larger pore types. Thanks to the interaction between the light-absorbing titanium dioxide and neighbouring chromium ions, to generate and store excited electrons, the MOF reduced CO₂ to CO and CH₄ with a performance comparable to solid-state and molecular catalysts.

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References

1. Nature 586, 549–554 (2020). doi: 10.1038/s41586-020-2738-2