In Situ Nanoscale Study of Electrocatalysts for Renewable Fuels

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The energy produced from renewable resources is playing an increasingly important role in today's power systems. Renewable chemical fuels (H2 from water splitting or fuels produced from CO2 reduction) can be used to store excess production of intermittent sources such as solar or wind for future use on the grid. The success of energy storage solutions depends on finding new materials and optimizing their properties and the reactions that occur at their surface. The structure and properties of electrode/electrolyte interfaces change depending on the environment and the applied potential. The overarching goal of my research program is to study these interfaces under realistic conditions, using in situ methods so as to gain information on the actual active structures at the interface and create new catalysts with improved performance. Methods such as scanning probe microscopy (SPM) and plasmonically enhanced Raman spectroscopy can achieve high sensitivity, surface specificity and nanoscale resolution. In high resolution experiments, an SPM tip will be used as an enhanced Raman hotspot to map the chemical structure at the nanoscale of the interface in situ with a resolution at 10nm or better, a technique known as tip enhanced Raman spectroscopy (TERS). The proposed research program combines several strategies to achieve my goal: 1. Nanosheet electrocatalysts for renewable fuels made of layered double hydroxides (LDH) and 2D transition metal nitrides/carbides materials ("MXenes") are prominent candidates for affordable electrocatalysts for the production of H2. The structure of these materials is known to change under catalytic conditions, while the activity is sensitive to the presence of dopants and the local structure (basal plane, steps, surface functionalization). My students and I will perform nanoscale in situ measurements to unravel local structure-activity relationships so as to guide the optimization of catalyst structure. 2. My team will investigate hybrid plasmonic electrocatalysts that possess a plasmonic resonance in the visible and can inject energetic charge carriers at the surface. This combination will increase the overall performance of the catalyst and give us a better control over the selectivity. Students will first study bimetallic plasmonic catalysts and will then combine optically active plasmonic structures with a catalytically active part: (a) molecular catalysts attached on the metal surface and (b) nanosheets of LDH and MXenes created in the context of my Discovery program. At the newly created plasmonic/catalytic interface, new catalytic sites will exist that will present a different activity and selectivity. The resulting expertise and instrumentation will be unique in Canada. My Discovery research program will be the foundation for future work on advanced materials such as metal organic frameworks (MOF), transition metal dichalcogenides and 2D carbon materials to solve renewable energy and sustainability problems.