Hydrogen from Water is more than a Fuel: Hydrogenations and Hydrodeoxygenations for a Biobased Economy

Worldwide a hydrogen-based economy is on the political agenda. Its centre forms molecular hydrogen (H₂ ) that should serve mainly as energy carrier and fuel. However, currently and foreseeable in the future H₂ is playing its main role as reactant in the chemical industry. Electrolytic generation and storage of H₂ gas is energy demanding and may hardly become economically at the large scale. We argue that in the overall transition towards an economy that is based on biomolecules and CO₂ as carbon feedstock electrochemical hydrogenations and hydrodeoxygenations in aqueous solutions need to be moved in the centre. Departing from the well-known fact that electrochemistry allows creating reactive hydrogen species from water, i. e. hydrogen in statu nascendi (H^. ), at ambient temperature and pressure we illustrate the existing diversity of reactions based thereon. We focus on examples of model compounds from thermal biomass pretreatment and products from real thermal biomass pretreatment (bio-oil). Consequently, we advocate that electrochemical hydrogenations and hydrodeoxygenations have to be further explored and interweaved into existing process lines.