ABSTRACT:In spite of the significant progress in the design and modification of materials for specific applications like hydrogen storage, there are still problems to achieve the desired levels of storage. Many MOFs have been designed and have also been synthesized but they are still not suitable enough or can meet the DOE standards due to moisture sensitive nature and the possibility of stability under other operating parameters
Hydrogen as fuel
Lower heating value 33.3 kWh/g= 123 MJ/kg (11.1kWh/g gasoline)8 MJ/L where as for gasoline 32 MJ/L2017 DOE target 5.5wt% = 40g/L volumetric capacity
wide range of Hydrogen storage materials
metal hydridescomplex hydrideschemical hydrides
carbohydratesclathrates
inorganic nanotutes organic materisls
MOFscarbon materials
Liquid density 70.8 kg/m3 at NTP
Physisorption methodson board reversible hydrides
(interstitial, covalent metal hydrides, amides and borohydrides
off board regenerable hydrides( hydrocarbons, ammonia borane,
alane)
The highest 99.5 mg/g at 56 bar and 77 K
164 mg/g at 77K 70 bar (176mg /g highest reported so far)
symbolic many metal framework of Zn(II), Cu(II) Mn(III),
Cr(III),La(III)
Design and synthesis of metal organic frameworks for hydrogen storage
In high boiling solvents like DMF, DEF (80-1300 C)solvo-thermal,
solubility solvent-ligand exchange kinetics,
rate of crystallizationcarboxylic acids, hetero-cycles containing
nitrogen
Where are we now?To meet DOE standards still a long way to goNew MOF with large surface area, pore volume, open metal sites, embedded metal catalysts facilitating hydrogen spill over have to be designed.
ABSTRACT:In spite of the significant progress in the design and modification of materials for specific applications like hydrogen storage, there are still problems to achieve the desired levels of storage. Many MOFs have been designed and have also been synthesized but they are still not suitable enough or can meet the DOE standards due to moisture sensitive nature and the possibility of stability under other operating parameters
