(349g) In-Situ Synthesis & Modeling of Cathodic Electrodeposition of Porphyrin Zr MOFs and Their Application Towards Electrochemical Reduction of CO2.

The electrodeposition method has been less explored in the field of Metal-Organic Frameworks (MOF) thin films in comparison to the solvothermal techniques. Cathodic deposition of MOFs provides a wide range of substrate choices which can then be deployed for various electrocatalysis applications. Porphyrin-based Zirconium MOFs have considerable conductivity post-activation, compared to other Zr MOFs or any other MOFs in general. This makes them excellent candidates for electrocatalysis applications. In previous studies, these MOFs have been deposited on glass substrates and deployed for electrocatalytic or photocatalytic application for CO₂-RR. Furthermore, these MOFs have been post-metalated with either Fe, Zn or Cu to enhance the Faradaic efficiency and overall activity to yield CO and trace amounts of CH₄. To further enhance this electrocatalytic activity of porphyrin Zr MOFs, a novel electrochemical synthesis technique has been developed to deposit them on conductive substrates. In-situ kinetic studies coupled with a COMSOL model have been developed to obtain insights into the deposition rate. Secondly, precise control of the synthesis conditions to obtain pure phases of the porphyrin MOFs have been demonstrated. Finally, the cathodically deposited thin films (Ti substrate) were deployed for the electroreduction of CO_2, which showed significant improvements in current density and Faradaic efficiencies than reported previously without post-metalation. A comparison study of non-metalated and metalated porphyrin Zr-MOFs towards CO₂-RR activity has also been conducted. To conclude, a theoretical hypothesis providing insight into the mechanism of the electroreduction reaction to the formation of C₁-products on these MOFs has been made.