Abstract: Homogeneous, solution-based electrocatalysts and heterogeneous solid electrocatalysts possess complementary strengths and weaknesses. There is growing interest in developing catalysts that take advantage of the strengths of both these paradigms. One well-established strategy is the modification of metallic electrocatalysts and their properties by forming self-assembled monolayers (SAMs) of organic molecules. Extending this motif, the work in this thesis aims to develop hybrid electrocatalysts consisting of metal surfaces modified by SAMs of transition metal complexes for CO2 conversion reactions. The small amount of material that forms a SAM and the highly dynamic nature of these surfaces under operating conditions make characterization a particular challenge. The first part of this presentation focuses on the development of in situ attenuated total reflectance
surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) and electrochemical quartz crystal microbalance (E-QCM) techniques for characterizing SAM formation and response to applied potential. A model SAM of 4-mercaptobenzonitrile was used to demonstrate the greater insight made possible by using these techniques in tandem. In a second project, these techniques are used to study SAMs of transition metal complexes supported by derivatives of the tris(2-pyridylmethyl)amine (tpa) ligand. Confirmation of SAM formation, characterization of behaviour under applied potential, and reactivity with substrate are studied. Under electrocatalytic CO2 reduction conditions, these complexes demonstrate the ability to support novel carbon monoxide (CO) binding modes which may be implicated in unique reactivity. Unfortunately, preliminary catalytic studies suggest that these surfaces are not stable over long periods of electrolysis. Therefore, development of other surface-anchoring strategies is needed. In light of this, a third project studies a novel anchoring approach involving a bridging chloride moiety between the metal surface and adsorbed metal complex. Further surface-supported reactivity of this binding mode is revealed wherein extrusion of the chloride yields the formation of a Au-Co bonded anchoring motif. It is hypothesized that the metal-metal bond in this binding mode is capable of supporting novel reactivity. The results of these three projects demonstrate the ability to form SAMs with transition metal complexes and highlight the abundance of novel reactivity this strategy can offer.