Catalyst Design for Dehydrogenation of Aromatic-Type Liquid Organic Hydrogen Carriers

One of the major hurdles that preclude the large-scale application of hydrogen energy is the lack of low-cost technology for the storage and transportation of green H2 produced from water electrolysis driven by renewable electricity. A promising strategy for tackling this challenge is the use of liquid organic hydrogen carriers (LOHCs) for the storage of green H2 because this technology is compatible with the infrastructure of the current chemical industry. Among the candidate LOHC systems, the aromatic-type LOHCs based on toluene-methylcyclohexane (TOL-MCH) and dibenzyltoluene and H18-dibenzyltoluene (DBT-H18-DBT) cycles have attracted tremendous attention from both academia and industry. In this review, we will summarize the fundamental understanding on the dehydrogenation reactions of aromatic-type LOHCs and the recent progress in the design of supported metal catalysts for the dehydrogenation of MCH and H18-DBT, which are critical steps in the LOHC systems. Moreover, we further make perspectives on the future developments of advanced catalytic materials for the H2 storage systems based on LOHC through integrated and interdisciplinary approaches.