Chemistry Reference
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Fig. 4.10 a
CO
2
adsorption and desorption isotherms of PAF-18-OH and PAF-18-OLi at 273 and
298 K. CO
2
adsorption of PAF-18-OLi obtained after 10 days exposure in humid air (
blue cir-
cles
) at 273 K;
b
plots of the isosteric heat of adsorption (Qst) for CO
2
of PAF-18-OH and PAF-
18-OLi;
c
gas sorption isotherms of CO
2
for PAF-26-COOH, PAF-26-COOLi, PAF-26-COONa,
PAF-26-COOK and PAF-26-COOMg at 273 K and 101 kPa;
d
the isosteric heats of adsorption for
CO
2
of PAF-26-COOH, PAF-26-COOLi, PAF-26-COONa, PAF-26-COOK and PAF-26-COOMg
as a function of gas uptake
PAF skeletons, their corresponding post-modified products are obtained. Although
the surface area of resulted product decreased, the CO
2
uptakes enhanced
(Fig.
4.10
a, c). Compared with the starting materials, the stronger interaction
between CO
2
molecules and the host materials (PAF-18-Li and PAF-26-COOM) is
verified by their higher isosteric heats of adsorption (Fig.
4.10
b, d), which is due to
the higher polarity of metal ions than that of protons and the small-pore effect.
4.4.3 Carbonization of POFs
POFs are composed of light elements such as C, H, O, N, B, etc. Therefore, they
are excellent precursors for preparing nanoporous carbon materials via high tem-
perature decomposition. Qiu et al. reported a series of carbonized PAF-1 s under
