The development of catalysts for the electrochemical synthesis of energy carriers is the subject of intensive research. The most common reactions are splitting of water into H2 and O2 and direct reduction of CO2 to fuels and feedstock for the the chemical industry. In this project a fundamental mechanistic understanding for both reactions will be developed. In addition, we will also focus on developing tools to predict acid-base properties at surfaces and in non-aqueous solvents. These tools are needed to develop more detailed mechanistic models but also open new possibilities in other areas of chemistry and related fields. The following topics will be considered: I) Water Splitting: We will study the reaction mechanisms responsible of the oxygen and hydrogen evolution reactions. Currently, the oxygen evolution reaction (OER) still suffers from a significant lack in efficiency and the need to rely on scarce and expensive metals (Ru, Ir, Pt). Our research will focus on developing a fundamental understanding of the underlying reaction mechanisms using IrO2 as a test material. Initial work will focus on the thermodynamic profile of competing reaction mechanisms. Contrary to earlier work a focus will also be placed on the release mechanism. These computations are complemented by the study of confinement effects (IrO2 doped into TiO2). Both systems are of high relevance for industrial OER catalysts. II) CO2 reduction: A promising alternative to water splitting is the direct reduction of CO2 to CO, methanol, formaldehyde, methane, etc. This process is appealing, since it offers direct access to feedstock for the chemical industry and liquid fuels. Unfortunately, we still lack active and selectivity catalysts. The development of suitable materials is further complicated by a lack of understanding of the underlying reaction mechanisms. This project will contribute by developing mechanistic insights which can be used for subsequent screenings or the rational design of improved catalysts. III) Acid-base chemistry in non-aqueous solvents and at surfaces: Acid-base chemistry is one of the most important reaction classes which affects all areas of chemistry but is also of relevance in e.g. biology and geology. We already possess efficient tools for pKa prediction in water but still lack the tools to accurately predict acidity of surface sites and in non-aqueous solvents. In our research group we will work on developing suitable methods to close these gaps. The catalysis related research relies on a combination of density functional theory (DFT), ab-initio molecular dynamics simulations (AIMD) and micro-kinetic modeing or kinetic Monte-Carlo simulations to extract the final reaction mechanisms. Contrary to most other research groups, we will focus equally on homogeneous and solid-state catalysts. This will enable us to build bridges between these still poorly connected research fields. For the purpose of developing methods for pKa prediction both full scale AIMD simulations or a QM/MM approach which combines DFT with (reactive)force fields is used to properly model the solvation shell. Ether simple oxide surfaces or simple organic molecules as test cases.