Today’s energy concerns require the development of suitable solutions for the storage of energy from renewable resources. Although the chemical storage of energy using molecular hydrogen as energy carrier is one of the best options, this type of energy storage requires the conversion of hydrogen to liquid organic hydrogen careers (LOHCs) for practical reasons. This goal is challenging and highly desirable at the same time. In comparison to dihydrogen, hydrogen storage in LOHCs offers easier handling and minimum dangers involved in their production, storage, and reconversion. To achieve efficient processes based on LOHCs highly active catalyst systems are required which ideally are based on cheap and abundant metals such as iron. This review summarizes recent advances in ironcatalyzed hydrogenation and dehydrogenation reactions, with relevance to reversible hydrogen storage in small molecules. It entails the dehydrogenation reactions of formic acid and methanol water mixtures, the reverse reaction, the hydrogenation of CO2, dehydrogenation of alcohols, and the hydrogenation of different carbonyl compounds as the formal reverse reaction, as well as hydrogenation and dehydrogenation reactions of N-heterocyclic compounds and hydrogen release reactions from amino boranes.
Philipps-Universität Marburg, Hans-Meerwein-
Straße, D-35043 Marburg, Germany; and Lehn Institute of Functional
Materials (LIFM), Sun Yat-Sen University (SYSU), Xingang Road West,
Guangzhou 510275, P. R. China
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