In our future energy economy, hydrogen will play an important role due to its high energy density and its CO2-free combustion. However, hydrogen storage is still challenging. Besides physical storage methods, hydrogen can be stored chemically in Liquid Organic Hydrogen Carriers (LOHC) like alcohols which enable safer and easier handling and transportation. For the effective storage and release of hydrogen (chem.: hydrogenation/dehydrogenation) catalysts are needed. During my doctoral studies my aim is to synthesize and investigate nucleophilic transition metal carbene complexes. Due to their interesting electronic properties, they will be applied as homogeneous catalysts in hydrogenation and dehydrogenation of LOHCs as well as in hydrogen-autotransfer reactions which allow the atom-economic synthesis of complex organic molecules in one step without the direct usage of molecular hydrogen. Based on the catalytic studies relations between (electronic) structure and catalytic performance will be investigated to design new catalysts with customized properties.