Active site imprinting on Ti oxocluster metal-organic frameworks for photocatalytic hydrogen release from formic acid

On-board hydrogen release from liquid organic carriers is a process that can make feasible the use of H 2 as a transportation fuel. Formic acid is considered as one of the most convenient liquid hydrogen organic carriers, and since it can be easily obtained from CO 2 , it is water soluble which makes it unnecessary to recover the H 2 -depleted byproducts. Compared to the more conventional thermal catalytic decomposition of formic acid, the use of light in combination with a photocatalyst has been much less explored. Herein, we report a new paradigm in MOF photocatalysis with the use of a microporous titanium oxocluster based metal-organic framework (Ti-MOF) endowed with formate-imprinted active sites, namely MIP-177-LT (MIP stands for Materials from Institute of Porous Materials of Paris, LT for Low Temperature), as a highly efficient photocatalyst for H 2 release from formic acid without the need to neutralize acidity or use sacrificial agents or noble metals. Noteworthily, a quantum efficiency of 22% has been determined for the photocatalytic H 2 release that is highly remarkable for a non-toxic noble metal-free photocatalyst. MOFs offer great potential in the photocatalytic hydrogen release from liquid organic carriers: towards the use of on-board H 2 as a transportation fuel.