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.; Wang, A.; Yang, X.; Allard, L. F.; Jiang, Z.; Cui, Y.; Liu, J.; Li, J.; Zhang, T., Single-atom catalysis of CO oxidation using Pt1/FeO x. Nature chemistry 2011, 3 (8), 634-641. Xia, C.; Qiu, Y.; Xia, Y.; Zhu, P.; King, G.; Zhang, X.; Wu, Z.; Kim, J. Y.; Cullen, D. A.; Zheng, D., General synthesis of single-atom catalysts with high metal loading using graphene quantum dots. Nature chemistry 2021, 13 (9), 887-894. Wu, J.; Xiong, L.; Zhao, B.; Liu, M.; Huang, L., Densely populated single atom catalysts. Small Methods 2020, 4 (2), 1900540. Huang, H.; Shen, K.; Chen, F.; Li, Y., Metal–organic frameworks as a good platform for the fabrication of single-atom catalysts. ACS Catalysis 2020, 10 (12), 6579-6586. Qu, W.; Chen, C.; Tang, Z.; Wen, H.; Hu, L.; Xia, D.; Tian, S.; Zhao, H.; He, C.; Shu, D., Progress in metal-organic-framework-based single-atom catalysts for environmental remediation. Coordination Chemistry Reviews 2023, 474 , 214855. Szilágyi, P.; Rogers, D.; Zaiser, I.; Callini, E.; Turner, S.; Borgschulte, A.; Züttel, A.; Geerlings, H.; Hirscher, M.; Dam, B., Functionalised metal–organic frameworks: a novel approach to stabilising single metal atoms. Journal of Materials Chemistry A 2017, 5 (30), 15559-15566. He, J.; Wang, J.; Chen, Y.; Zhang, J.; Duan, D.; Wang, Y.; Yan, Z., A dye-sensitized Pt@ UiO-66 (Zr) metal–organic framework for visible-light photocatalytic hydrogen production. Chemical communications 2014, 50 (53), 7063-7066. Elcheikh Mahmoud, M.; Audi, H.; Assoud, A.; Ghaddar, T. H.; Hmadeh, M., Metal–Organic Framework Photocatalyst Incorporating Bis(4′-(4-carboxyphenyl)-terpyridine)ruthenium(II) for Visible-Light-Driven Carbon Dioxide Reduction. Journal of the American Chemical Society 2019, 141 (17), 7115-7121. Hendrickx, K.; Joos, J. J.; De Vos, A.; Poelman, D.; Smet, P. F.; Van Speybroeck, V.; Van Der Voort, P.; Lejaeghere, K., Exploring lanthanide doping in UiO-66: a combined experimental and computational study of the electronic structure. Inorganic Chemistry 2018, 57 (9), 5463-5474. Yu, H.; Joo, P.; Lee, D.; Kim, B. S.; Oh, J. H., Photoinduced Charge‐Carrier Dynamics of Phototransistors Based on Perylene Diimide/Reduced Graphene Oxide Core/Shell p–n Junction Nanowires. Advanced Optical Materials 2015, 3 (2), 241-247.