Structural and adsorption studies of activated carbons derived from porous phenolic resins

Several carbon adsorbents characterised by different matrix-confined microporosity and textural meso- and macroporosity were prepared by heat-treatment of porous phenolic resins. These were investigated using adsorption, one-pass temperature-programmed desorption (OPTPD) with mass-spectrometry (MS) control (300–850 K), 1H NMR spectroscopy (190–280 K) and thermally stimulated depolarisation current (TSDC, 90–260 K) methods. Variations in resin composition and carbon preparation conditions allow us to control microporosity and/or textural porosity as well as adsorptive properties (energy of adsorption, adsorption potential and Gibbs free energy of adsorption) of the carbon adsorbents. According to the NMR and TSDC data, a portion of water (small clusters) in aqueous suspensions of the carbon adsorbents has the same structure as in bulk water. However, extended water structures undergo significant changes in the presence of carbon or carbon/nanosilica. TSDC-cryoporometry gives pore size distributions for carbons similar to those obtained using standard adsorption methods.