Hydrogen Storage in Porous Materials: Status, Milestones, and Challenges

Abstract

In this account the most relevant advancements in hydrogen storage in porous materials are presented. These include the current state-of-the-art, the challenges which have been overcome, and the hurdles which still remain. The most important milestones which will be discussed in this work will be the development of new apparatuses capable of delivering reliable results under a broad range of operational conditions, in which analysis temperature and pressure are critical parameters. Other aspects such as the materials storage capacity in gravimetric and volumetric terms will be critically discussed to identify the conditions required from an ideal material. Finally, different upgrade possibilities from modifying the adsorbate-adsorbent interaction to using rigid or flexible materials will be presented and put into perspective with current literature.

Elimination of 4‐chlorophenol in aqueous solution by the Novel Pd/MIL‐101(Cr)‐Hydrogen‐Accelerated catalytic fenton system

“…Both of them may result the low production of Fe 2+ . On the other hand, it indicated that the MIL‐101(Cr), based on its porosity and H 2 storage, could extend the retention time of H 2 in solution. That promoted the reduction efficiency of Fe 3+ by activating hydrogen.…”

“…In recent years, the metal–organic frameworks (MOFs) material, with high specific surface area, tunable and large pore size, and diversity open metal sites, are showing great application potential of gas separation, sensing, energy storage and catalysis . Especially in the field of hydrogen storage, these properties facilitate the adsorption of H 2 on the surface of it.…”

Hydrogen Production from Formic Acid Attained by Bimetallic Heterogeneous PdAg Catalytic Systems

“…The relative moderate hydrogen capacity of 4.4 wt.% might seem to be its weak point as compared to other LOHC [16]. However, its high density of 1.22 g/cm 3 leads to a volumetric capacity of 53 gH 2 /L, equivalent to an energy density of 1.77 kW·h/L, which is larger than the value of compressed hydrogen at 70 MPa [9,17].…”

“…Formic acid (methanolic acid, HCOOH, FA), the simplest carboxylic acid (pK a = 3.75), is an outstanding LOHC candidate, which not only encompasses most of the features listed above but also, it is a product of the hydrogenation of CO 2 [14,15].The relative moderate hydrogen capacity of 4.4 wt.% might seem to be its weak point as compared to other LOHC [16]. However, its high density of 1.22 g/cm 3 leads to a volumetric capacity of 53 gH 2 /L, equivalent to an energy density of 1.77 kW·h/L, which is larger than the value of compressed hydrogen at 70 MPa [9,17].The production of H 2 from FA was firstly investigated by Coffey in 1967 [18], but it was not until 2008 when the interest of FA as a LOHC was renewed thanks to the independent investigations carried out by Laurenczy and Beller [19][20][21]. Along these years, studies dealing with the production of H 2 from FA have been carried out by using both, homogeneous and heterogeneous catalysts of diverse composition [22][23][24].…”

“…gasification of biomass/biofuels and water splitting), it is mostly produced via steam reforming process, which indeed is not sustainable because it uses fossil fuels and CO 2 is produced [8]. Moreover, aside from that, there are also significant limitations related to its difficult storage and delivery [9], as well as safety issues derived from its high flammability and potential explosiveness [10]. A promising alternative to overcome those limitations is the production of H 2 from hydrogen carrier molecules.…”