Recent Progress and New Perspectives on Metal Amide and Imide Systems for Solid-State Hydrogen Storage

Abstract

Hydrogen storage in the solid state represents one of the most attractive and challenging ways to supply hydrogen to a proton exchange membrane (PEM) fuel cell. Although in the last 15 years a large variety of material systems have been identified as possible candidates for storing hydrogen, further efforts have to be made in the development of systems which meet the strict targets of the Fuel Cells and Hydrogen Joint Undertaking (FCH JU) and U.S. Department of Energy (DOE). Recent projections indicate that a system possessing: (i) an ideal enthalpy in the range of 20-50 kJ/mol H 2 , to use the heat produced by PEM fuel cell for providing the energy necessary for desorption; (ii) a gravimetric hydrogen density of 5 wt. % H 2 and (iii) fast sorption kinetics below 110 • C is strongly recommended. Among the known hydrogen storage materials, amide and imide-based mixtures represent the most promising class of compounds for on-board applications; however, some barriers still have to be overcome before considering this class of material mature for real applications. In this review, the most relevant progresses made in the recent years as well as the kinetic and thermodynamic properties, experimentally measured for the most promising systems, are reported and properly discussed.

Enhancement Effect of Bimetallic Amide K2Mn(NH2)4 and In-Situ Formed KH and Mn4N on the Dehydrogenation/Hydrogenation Properties of Li–Mg–N–H System

“…In the last decades, the possibility to store hydrogen in a solid state using metal hydride-based systems was investigated [3,4]. In this regard, several light metal complex hydrides such as alanates, borohydrides and amide-hydride systems were studied [5][6][7][8][9][10][11]. In particular, the reactive hydride composite (RHC) systems based on amide-hydrides are considered as promising hydrogen storage media, due to their suitable hydrogen Starting materials for the synthesis of K 2 Mn(NH 2 ) 4 are potassium (cubes, Sigma Aldrich, 99.5% purity, in mineral oil) and manganese (powder, Sigma Aldrich, ≥99% purity).…”

A new mutually destabilized reactive hydride system: LiBH4–Mg2NiH4

“…The crucial parameters of the Rietveld analyses are summarized in Table 1 . The reference material has the smallest cell parameters and consequently the lowest cell volume of 181.57 Å 3 . In addition, all site occupancies were calculated to be 1 yielding an atomic ratio of Mg ( Fig.…”

“…In the last decades, the hydrogen absorption and desorption properties of complex metal hydrides such as borohydrides [1,2] , amides [3] and alanates [4] have been extensively investigated, due to their high gravimetric hydrogen storage capacity [5,6] . However, the reaction enthalpies of the complex metal hydrides are usually too high for most applications.…”

Metals in Hydrogen Technology

“…In recent decades, complex metal hydrides such as borohydrides, alanates, and amides have been intensively investigated as potential material for hydrogen storage applications [2][3][4][5].…”