Two‐Phase System Utilizing Hydrophobic Metal–Organic Frameworks (MOFs) for Photocatalytic Synthesis of Hydrogen Peroxide

Abstract

Much effort has been devoted to photocatalytic production of hydrogen peroxide (H 2 O 2 )a sa na lternative to fossil fuels.F roma ne conomic point of view,r eductive synthesis of H 2 O 2 from O 2 coupled with the oxidative synthesis of value-added products is particularly interesting.W eh erein report application of MIL-125-NH 2 ,aphotoactive metalorganic framework (MOF), to ab enzylalcohol/water twophase system that realized photocatalytic production and spontaneous separation of H 2 O 2 and benzaldehyde.H ydrophobization of the MOF enabled its separation from the aqueous phase.T his resulted in enhanced photocatalytic efficiency and enabled application of various aqueous solutions including extremely low pH solution which is favorable for H 2 O 2 production but fatal to MOF structure.I na ddition, ah ighly concentrated H 2 O 2 solution was obtained by simply reducing the volume of the aqueous phase.

Production of Hydrogen Peroxide by Photocatalytic Processes

“…With the deposition of NiO nanoparticles on the MIL-125-NH 2 ,t he production of H 2 O 2 was accelerated through fast disproportionation of the active O 2 C À intermediate.However,one apparent drawback was that the produced H 2 O 2 mixed with benzaldehyde and acetonitrile, and thus an energy-consuming separation process was needed to separate the H 2 O 2 and benzaldehyde after the photocatalytic reaction. To overcome this drawback, the authors [119] developed at wo-phase system consisting of benzyl alcohol in the presence of Ir(OH) 3 (red circles) and its absence (blue squares). b) Proposed mechanism.…”

A comparative perspective of electrochemical and photochemical approaches for catalytic H2O2 production

“…7). 124 Moreover, the concentration of the obtained H 2 O 2 solution can be easily tuned by the volume of the aqueous phase. In addition, metal coordination polymers have also been investigated as robust photocatalysts for H 2 O 2 production, which was mainly inspired by the structure of superoxide dismutases (SODs) in nature systems consisting essentially of late transition metal ions as central atoms and proteins as organic ligands.…”

Self‐Generation of Surface Roughness by Low‐Surface‐Energy Alkyl Chains for Highly Stable Superhydrophobic/Superoleophilic MOFs with Multiple Functionalities

“…Jiang and co‐workers reported a method for coating polydimethylsiloxane (PDMS) on the UiO‐66 crystal to improve its hydrophobicity, catalytic activity, and selectivity . Recently, the Yamashita group introduced C 7 alkyl chains onto MIL‐125‐NH 2 by PSM to enable the photocatalytic production and spontaneous separation of H 2 O 2 /benzaldehyde in a benzyl alcohol/water two‐phase system . In contrast, the synthetic approach focused on the fabrication of a rough surface, which is popular for carbon‐ and metal‐based hydrophobic materials, remains in its infancy.…”