Methylbenzyl Naphthalene: Liquid Organic Hydrogen Carrier for Facile Hydrogen Storage and Release

Abstract

A new homocyclic methylbenzyl naphthalene (MBN) compound has been developed as a novel liquid organic hydrogen carrier (LOHC) medium with a high gravimetric hydrogen storage capacity of 6.44 wt % and good dehydrogenation ability. According to the results of theoretical calculations of designed MBN, MBN media possesses one of the lowest dehydrogenation enthalpies (<56 kJ mol H2 −1) among homocyclic LOHC media. The Friedel−Craft alkylation reaction allows the formation of an MBN regioisomeric mixture, which minimizes the production cost for practical applications. This mixture exists as a liquid with a high boiling point (>623 K) at ambient temperature. The H 2 storage efficiency of MBN was optimized to achieve a yield of greater than 99% using a new Ru-based catalyst. The reaction monitoring study suggests the stepwise hydrogenation reaction of aromatic rings, which allows the proposed hydrogenation mechanism. The extraction of H 2 from hydrogen-rich H 16− MBN was conducted via a dehydrogenation reaction (yield > 99%) using a Pt/CeO 2 catalyst, which enabled fast H 2 release. The faster and facile dehydrogenation of MBN compared to the other reported homocyclic LOHC media coincides with the theoretical calculation results.

Converting Waste Plastic to Liquid Organic Hydrogen Carriers

“…However, these processes are associated with additional challenges including low adsorption affinity for inert gases, [10] contamination of metal particles during dehydrogenation, and high catalyst recovery costs. [11] The dehydrogenation can be performed in a batch reactor without the need for a carrier gas and thus separation, [12] but with limitations in scalability.…”