Abstract
We have doped polyfurfuryl alcohol derived activated carbon (PFAC) with two alkali metals, potassium (K) and lithium (Li) by prior reacting the metals with naphthalene in presence of tetrahydrofuran (THF) followed by introducing them to pristine PFAC. THF molecule causes minor alteration in the microstructure of PFAC as confirmed by the Raman spectra, X-ray diffraction and pore textural analysis. Raman spectra and X-ray diffraction indicated a slight localized ordering towards the stacking defects of disordered carbon, like PFAC which can be attributed to the movement of THF molecules within the internal planes of graphene sheets. Pore textural analysis confirmed the lowering specific surface area and pore volume of both K and Li doped PFACs.(BET SSA: 1378 m2/g (PFAC); 1252 m2/g (K-PFAC); 1081 m2/g (Li-PFAC)) Volumetric hydrogen adsorption measurement at the temperatures of 298, 288, 273 and 77 K and pressure up to 1 bar indicated the enhanced adsorption potential imposed by the presence of alkali metals, which can be reconfirmed by the additional heats of adsorption of metal doped PFACs (Li-PFAC: -(10 - 11) kJ/mol; K-PFAC: -(16 -19) kJ/mol) compared to pristine PFAC (-9.6 kJ/mol).
