Tuning Peripheral Functionality of Molecular and Interfacial Electrocatalysts to Influence Reaction Pathways

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The development of more efficient and selective catalysts for electrochemical reduction of carbon oxides is critical to lowering global greenhouse gas emissions and transitioning away from fossil fuels. New catalyst designs and a more detailed understanding of fundamental reaction mechanisms are needed in order to realize the goal of a commercially viable carbon oxide electrolyzer. The proposed research program will design and study homogeneous and heterogeneous electrocatalysts by bringing together synthetic, electrochemical, and spectroscopic approaches. We will aim to precisely tune the local reaction environment through targeted installation of specific chemical groups that can alter the outcome of reaction pathways. By investigating the mechanistic differences in well-defined systems, we hope to eventually inform rational design of catalysts with activities and selectivities rivaling the best enzymatic systems. Our research program comprises three focus areas spanning homogeneous and heterogeneous catalysis. The first objective is to modify the second coordination sphere of homogeneous catalysts through introduction of a second metal center and to examine the electrocatalytic activity for a range of carbon oxide reduction reactions (CO2, CO, bicarbonate, etc.). It is proposed that the presence of two metal centers rather than one will enable new cooperative interactions with carbon oxide substrates that could potentially enable previously unobserved reactivity. The second objective is to study reaction mechanisms on the aforementioned catalysts to understand the role of the second coordination sphere groups in detail. These efforts will be enabled by electrochemical and advanced spectroscopic techniques, including time-resolved infrared (TR-IR) spectroscopy. In parallel, we will work on a third objective, which is to extend these ideas of chemical control over local reaction environment to heterogeneous electrode interfaces. Specifically, we will employ attenuated total reflectance-surface enhanced IR absorption spectroscopy (ATR-SEIRAS) under operating conditions to investigate how reaction pathways on the surface can be manipulated by molecular design. We seek to become an internationally recognized lab with a unique skillset that includes advanced time-resolved and surface-enhanced FT-IR capabilities to address challenging problems at the forefront of renewable energy catalysis. The proposed research will provide excellent training opportunities to prepare HQP (highly qualified personnel) for jobs in Canadian chemical and clean technology industries and in academia.