Material Demands for Storage Technologies in a Hydrogen Economy

Table 1

Hydrogen properties.

Atomic weight	1.0079	g mol^−1
Van der Waals radius	120	pm
Covalent radius	31	pm
ΔH (H2⇀ 2 H)	436	kJ mol^−1
Density at 273 K and 0.1 MPa	0.0899	g l^−1
Liquid density (20.25 K)	70.8	g l^−1
Boiling point	20.25	K
Critical temperature	32.97	K
Critical pressure	1.276	MPa
Self-ignition temperature	747	K
Flammability limit in air	4.1–74.2	Vol.%
Explosive limits in air	18.3–59	Vol.%
Diffusion coefficient in air	0.634	cm^2 s^−1