Bridging Thermodynamic and Kinetic Processes in Electrochemically Relevant Calculated Pourbaix Diagrams

The transition states in kinetic processes are often experimentally elusive. Computational tools can be used to gain an atomistic perspective into these transition states. A learning tool to guide students through the complexities of the theory while gaining an appreciation for the coupling of thermodynamic and kinetic processes is explored here. A computational protocol which hinges on combining calculated free-energy profiles along proposed mechanistic pathways with electrochemically relevant Pourbaix diagrams has been proposed with the design of molecular catalysts for hydrogen production and oxidation in mind. Two experimentally characterized species are used to test the protocol; the outcome suggests interesting ways to tune a catalyst for optimal activity. This protocol can be used as either a pedagogical tool or a research directive on how to combine theoretical analysis to experimental electrochemical studies.