Hydrogen Storage by Liquid Hydrogen Carriers: Catalyst, Renewable Carrier, and Technology - A Review

Hydrogen has attracted widespread attention as a carbon-neutral energy source, but developing efficient and safe hydrogen storage technologies remains a huge challenge. Recently, liquid organic hydrogen carriers (LOHCs) technology has shown great potential for efficient and stable hydrogen storage and transport. This technology allows for safe and economical large-scale transoceanic transportation and long-cycle hydrogen storage. In particular, traditional organic hydrogen storage liquids are derived from nonrenewable fossil fuels through costly refining procedures, resulting in unavoidable environmental contamination. Biomass holds great promise for the preparation of LOHCs due to its unique carbon-balance properties and feasibility to manufacture aromatic and nitrogen-doped compounds. According to recent studies, almost 100% conversion and 92% yield of benzene could be obtained through advanced biomass conversion technologies, showing great potential in preparing biomass-based LOHCs. Overall, the present LOHCs systems and their unique applications are introduced in this review, and the technical paths are summarized. Furthermore, this paper provides an outlook on the future development of LOHCs technology, focusing on biomass-derived aromatic and N-doped compounds and their applications in hydrogen storage.