Chemistry Reference
In-Depth Information
Fig. 4.6 a
N
2
adsorption and desorption isotherms of PAF-18-OH (
black symbols
) and PAF-18-OLi
(
red symbols
) at 77 K;
b
the pore size distribution of PAF-18-OH (
black circles
) and PAF-18-OLi
(
red circles
);
c
H
2
adsorption and desorption isotherms of PAF-18-OH and PAF-18-OLi at 77 and
87 K;
d
plots of H
2
adsorption Qst of PAF-18-OH and PAF-18-OLi versus the H
2
uptake
4.3 Methane Storage Using POFs
Besides the renewable energy source H
2
, CH
4
also seems to be a rising star
in clean energy, with the power density of 15.5 kW h kg
−
1
and a worldwide
storage. Currently, the main problem with CH
4
application lies in the efficient
storage and transport of this highly flammable gas. Concerns over the stability
and cost associated with the application of MOFs in methane adsorption have
led to the evaluation of POFs as alternative methane sorbents. Their tolerance
of water and metal-free skeletons make POFs attractive options in the field of
methane storage. Furthermore, many POFs exhibit exceptionally high surface
areas and low framework density, which make them ideal in the gravimetric
storage of methane. The investigations on methane adsorption in nanoporous
organic polymers are much less than that of widely studied hydrogen sorption.
To satisfy the demand on CH
4
transport, the materials should have high CH
4
adsorption capacities.
