Global physical storage in porous materials, the liquefying has

Global
warming, climate changes, food print rises, energy crisis and all related
issues have been discussed enormously in last decades. However, in spite of
increasing the overall awareness about fossil fuels challenges, yet there
remains some disagreement as to whether the beneficial balance of renewable
energies will be positive or negative. Although great investments in
sustainable energies such as solar, wind, geothermal, biofuel, hydropower and
fuel cells have been pushing forward technological boundaries, still there is a
huge gap between what is expected and the results. The technology of solar
cells as photovoltaic which was assumed supplying considerable balance of
energy basket, do not comply this prospect. Consequently,
for meeting the future demand of energy, applicable technologies are needed. One
of the promising green technologies is fuel cell. As an electrical source for
household usage and also for propelling vehicles, fuel cell technologies can
have significant role in energy security. This technology can be derived by
pure hydrogen as a fuel and through the process called electrochemical make
current for domestic or industrial usage. However, fuel cells use different
fuels to harvest electricity, if the hydrogen uses as fuel the product will be
clear and efficient(namely water, currency and heat). Hydrogen can be considered
as renewable energy carriers if it provides from renewable resources such as
Air or Water, while can be reached from hydrocarbons in reforming process. Despite
other fuels, hydrogen energy can be used directly and also indirectly as burn
in the car fuel tanks or alters to electricity respectively. Thus, the concept
of hydrogen economy has been widely debated among scientist and engineers recently,
due to being simple and abundant. One of the controversial issues in this
technology which has been being studied by various engineers is how hydrogen
can be stored1. Enormously low density of hydrogen makes this
technology extremely expensive. It means for storing this element, lots of
energy is required. Among various ways of storing hydrogen such as compressing,
liquefying, chemical storage and physical storage in porous materials, the
liquefying has been found the most expensive one2. Although using metal hydrides and relevant materials
for chemical adsorption also offers very safe to store hydrogen, this
technology is not affordable. Nonetheless, these technologies have not met the
amount of hydrogen which can be supplied for transport purposes3, 4.