Chemical activation of tannin–furanic carbon foams

New tannin-derived/furanic carbon foams with high surface areas were obtained by chemical activation. ZnCl2 and H3PO4 were used as activating agents and the stability of the foams structures obtained was evaluated. In addition to conventional textural analysis, the activated foam samples were analysed by nuclear magnetic resonance (NMR) and temperature programmed desorption with mass spectrometry analysis (TPD-MS). 13C NMR analysis has allowed to understand the chemical rearrangements occurring and 1H NMR has allowed to study interactions of the foam with water. TPD-MS yielded information on the surface chemistry of the activated carbon. Chemical activation was found to be effective for both treatments: the surface area increasing from 36 m2/g up to 1875 m2/g and 1265 m2/g for foams synthesised respectively with zinc chloride and phosphoric acid. It has been demonstrated that the final carbon foams exhibit mainly micropores. Moreover, different surface chemistry were obtained depending on the chemical treatment used. Therefore, it was shown that carbon foams with high surface areas and tailored surface chemistry can be synthesised from this biomass based precursor.