Due to the increasing importance of hydrogen as an energy carrier in the transition to fully renewable energy systems, alternative technologies to the expensive storage and transportation of pure elemental hydrogen are required. The liquid organic hydrogen carrier (LOHC) technology represents a promising method for the chemical storage of hydrogen and can make use of the existing energy infrastructure for liquid fuels. Hydrogen storage in the LOHC system proceeds via the reversible hydrogenation and dehydrogenation of organic molecules in repeatedly applied storage cycles without emitting CO 2 . [1] One prominent LOHC system is based on the dibenzyltoluene (H0-DBT)/perhydro-dibenzyltoluene (H18-DBT) couple: H0-DBT acts as a hydrogenlean carrier. In an exothermic catalytic hydrogenation step, H0-DBT is loaded with hydrogen and forms the hydrogen-rich carrier H18-DBT. This compound can release hydrogen in an endothermic catalytic dehydrogenation reaction. The released hydrogen can then be used directly in a fuel cell. The major advantages of the LOHC technology are hydrogen storage and transport in a liquid state with very high volumetric and comparatively high gravimetric energy densities under ambient conditions.In general, it would be advantageous to combine the dehydrogenation and the fuel cell reaction in a single process step, i.e., to use the hydrogen-rich LOHC compound directly as fuel for a fuel cell. However, direct electrification of H18-DBT in fuel cells, has not been realized at an attractive performance level so far. [2] Instead, it has been found that secondary alcohols, such as 2-propanol, are attractive fuels for direct electrification. [3] Most interestingly, the dehydrogenation of 2-propanol in a proton exchange membrane (PEM) fuel cell setup stops at acetone and no CO 2 is formed. [4] The resulting acetone can be recharged with hydrogen via catalytic hydrogenation [5] or transfer hydrogenation. [6] Sievi et al. demonstrated that transfer hydrogenation from H18-DBT to 2-propanol can be highly energy efficient (>50%). The hydrogen-rich H18-DBT releases hydrogen in contact with acetone, producing 2-propanol and the hydrogen-lean H0-DBT. By feeding the fuel cell with 2-propanol, acetone is formed, which in turn can be converted back into 2-propanol

Background: Transcription factor 4 (TCF4) has been linked to human neurodevelopmental disorders such as intellectual disability, Pitt-Hopkins Syndrome (PTHS), autism, and schizophrenia. Recent work demonstrated that TCF4 participates in the control of a wide range of neurodevelopmental processes in mammalian nervous system development including neural precursor proliferation, timing of differentiation, migration, dendritogenesis and synapse formation. TCF4 is highly expressed in the adult hippocampal dentate gyrus – one of the few brain regions where neural stem / progenitor cells generate new functional neurons throughout life.Results: We here investigated whether TCF4 haploinsufficiency, which in humans causes non-syndromic forms of intellectual disability and PTHS, affects adult hippocampal neurogenesis, a process that is essential for hippocampal plasticity in rodents and potentially in humans. Young adult Tcf4 heterozygote knockout mice showed a major reduction in the level of adult hippocampal neurogenesis, which was at least in part caused by lower stem/progenitor cell numbers and impaired maturation and survival of adult-generated neurons. Interestingly, housing in an enriched environment was sufficient to enhance maturation and survival of new neurons and to substantially augment neurogenesis levels in Tcf4 heterozygote knockout mice.Conclusion:The present findings indicate that haploinsufficiency for the intellectual disability- and PTHS-linked transcription factor TCF4 not only affects embryonic neurodevelopment but impedes neurogenesis in the hippocampus of adult mice. These findings suggest that TCF4 haploinsufficiency may have a negative impact on hippocampal function throughout adulthood by impeding hippocampal neurogenesis.