Catalysts for Hydrogen Production from Heavy Hydrocarbons

Sustainable hydrogen production is a key target in the development of future alternative energy systems for providing a clean and affordable energy supply. Nowadays, the lack of widely available sources of H-2 dictates the use of logistic fuels, multicomponent mixtures containing a large number of hydrocarbons, in the near term as a way to facilitate the introduction of hydrogen in energy systems, as this option entails no extra capital cost for developing the infrastructure and so relieves the economic pressure on moving to a hydrogen economy. A further advantage is that developments in the field of hydrogen generation from conventional fuels could be applied to the extraction of hydrogen from other liquid fuels that contain heavy hydrocarbons produced from biomass, thereby providing a bridge for the transition of hydrogen production from fossil fuels to renewable production from biomass. Catalysts for hydrogen production from heavy hydrocarbons have made remarkable progress in recent years, but there are various technical challenges, mainly low activity and durability, that need to be addressed for future improvement. This Review provides an overview of the research progress on hydrogen production from logistic hydrocarbons. The challenges for catalysts applied to the reforming of logistic hydrocarbons are discussed in detail to reveal the specific needs for each of the main reforming processes used with such hydrocarbons: Steam reforming, partial oxidation, and autothermal reforming. The four challenges for each process are activity, sulfur poisoning, carbon formation, and sintering. An overview is provided of the research strategies and approaches adopted in search of catalysts that respond to the above challenges; that is, selection of active phase, promoters, and supports and control of the synthesis of materials for customizing the crystallinity, electronic structure and morphology of catalysts at the nanoscale.