Research
Property/Reactivity Relationships of Electrified Interfaces
A major research focus of our laboratory is to explore how the properties of (photo-) electrocatalytic interfaces control the product selectivity of reaction processes. The product distributions of many technologically interesting reactions, such as CO2 reduction, are profoundly affected by the properties of the liquid side of the interface, i.e. the distribution of excess ions in the electrochemical double layer, the structure of interfacial water, etc. (see scheme). Our research team characterizes the properties of the interface by surface-selective infrared and Raman spectroscopies, and concurrently detects the reaction products evolving from the same interface in real time by differential electrochemical mass-spectrometry. This approach allows us to correlate measured interfacial properties (e.g. the interfacial water structure) with observed product distributions.
Structural Evolution of Catalysts
Another research direction focuses on understanding the key factors that control the morphological evolution of catalysts during synthesis and under operating conditions. The chemical and structural characteristics of the vast majority of catalytic interfaces evolve under operating conditions. The dynamic nature of the catalytic interface pose formidable experimental challenges for the establishment of property-activity relationships. We use spectroscopic methods to monitor the structural evolution of catalysts during their formation and under operating conditions.
Mechanisms in Metallaphotocatalysis
The another research area of our laboratory focuses on mechanistic studies in the field of metallaphotocatalysis, a new field of organometallic synthesis that merges photocatalysis with transition metal catalysis. Photocatalytic schemes often suffer from a limited substrate scope, i.e. the reactant molecules need to be ”pre-activated” for reaction by virtue of their chemical structure. To develop more efficient synthetic strategies applicable to a broad range of substrates, it is essential to identify the critical mechanistic steps that lead to low product yield. Using time-resolved IR spectroscopy, we conduct mechanistic case studies of prototypical photocatalytic systems to reveal how energy and/or electron-transfer events are temporally related to desired and undesired bond transformations.