Modified Metal Organic Frameworks Supported Ni Single Atom Catalyst for Enhanced Photocatalytic Hydrogen Evolution Reaction

Abstract Downsizing metal nanoparticle catalysts to form single-atom catalysts (SACs) has proven to be one of the best ways to enhance the catalysts’ activity and selectivity 1-2 due to their unique characteristics such as nearly 100% atom utilization and well-defined active sites. 3 However, the broad application of SACs in catalytic reactions is limited by their poor stability as they possess high surface energy and thus tend to aggregate and form nanoclusters or nanoparticles. 4 To address this challenge, various supports such as metal oxides, carbon materials, and porous materials are widely used to stabilize the SACs. 5 Metal organic frameworks (MOFs), a class of porous crystalline materials, have proven to be an ideal candidate to support SACs owing to their high surface area, high porosity, and abundant potential anchoring sites. 6 It has been shown that immobilizing SACs on MOFs, which forms MOF supported SACs, can integrate the unique properties of SACs and MOFs and led to remarkable catalytic activity, selectivity, and stability toward various catalytic reactions. 6-8 Application of MOF supported SACs in photocatalysis, organic linkers of metal-organic frameworks act as photosensitive units, 9 However most pristine metal-organic frameworks possesses poor light absorption properties due to wide band gap. 9 To enhance the light harvesting properties of the metal organic framework its organic linker is functionalized. 10-11 In my poster presentation, I will present my work where post-synthetic modification of UiO-66-NH 2 MOF linker with 3,4,9,10 perylene tetracarboxylic dianhydride (PDA) an organic molecule with broad absorption edge, 12 and immobilization of Ni single atom catalyst on the zirconium cluster of the MOF was done. This resulted in enhanced optical properties and charge separation efficiency which was proved by a combination of UV-visible spectroscopy (UV-Vis), photoelectrochemical techniques, and X-ray absorption spectroscopy (XAS). Observed photophysical effects posed by the modifications of the UiO-66-NH 2 were evaluated by photocatalytic hydrogen generation. References Yan, J.; Kong, L.; Ji, Y.; White, J.; Li, Y.; Zhang, J.; An, P.; Liu, S.; Lee, S.-T.; Ma, T., Single atom tungsten doped ultrathin α-Ni (OH) 2 for enhanced electrocatalytic water oxidation. Nature communications 2019, 10 (1), 1-10. Jiao, L.; Jiang, H.-L., Metal-organic-framework-based single-atom catalysts for energy applications. Chem 2019, 5 (4), 786-804. Qiao, B.;