EDL-assisted thermochemical heterogeneous catalysis of CO2

Thermochemical heterogeneous catalysis or themocatalysis in short, is one of the most important processes in chemical synthesis of molecules. The Fischer-Tropsch process is maybe the best-known example where syngas, a mixture of carbon monoxide (CO) and hydrogen (H2) gasses, is converted over a catalyst bed at elevated temperatures and pressures to hydrocarbons or fuels. It is, for example, considered for synthesis of synthetic kerosine from CO2 for sustainable aviation. The Fischer-Tropsch process is well established in industry, but unfortunately relies on CO and H2 produced from fossil fuels, e.g. by steam reforming of methane. Using hydrogen from water electrolysis, instead, the direct hydrogenation of CO2 by thermocatalytic means is currently being investigated as green alternative. Another route which is being investigated it the direct electrocatalysis of CO2 and water to hydrocarbons. In this PhD project, we will combine the best of both worlds and investigate electrical-double-layer (EDL) assisted thermochemical heterogeneous catalysis to boost the catalytic activity towards gas conversion reaction. Electrically addressable catalysts enable to control the surface charge of the electrical double-layer (EDL) at the catalyst, which in its turn affects the reaction mechanism (selectivity) and reaction rate (activity/conversion efficiency). In this PhD topic you will develop electrochemical cells with specialized gas-diffusion-electrodes to study the effect of applied potential and surface charge on the thermocatalytic conversion. Model chemical systems will be used to prove the principle and develop the optimum conditions which will be transferred towards the efficient hydrogenation of CO2 to methanol in collaboration with the researchers in the team. Reaction rate enhancement by non-Faradaic or capacitive potential control in electrochemical cells has been shown already in literature. However, as these electrodes have very low catalyst loadings, they cannot be used in industrially relevant context. The electrochemical storage and conversion team in imec has developed a large area metal nanomesh electrode which is currently being developed for electrocatalytic conversion and will be explored further for the purpose of EDL-assisted thermocatalytic conversion.