Pore morphological identification of hydrotalcite from nitrogen adsorption

The characteristic energy of nitrogen adsorption in a meso-porous hydrotalcite at 77 K demonstrates the fractality over wider range of pore sizes including meso and macro-pores. More irregular, wider pore-size distribution exhibits higher adsorption potential than that with more regular, narrower pore-size distribution. The changes in differential molar entropy during the adsorption indicate that an irreversibly chaotic process associated with transition from a disordered gaseous state to a more ordered adsorbed state occurs. The differential entropy of adsorption decreases at increasing fractality. The increase in ‘pure’ isosteric enthalpy of adsorption with increasing fractality indicates that the energy is closely related to the pore-size distribution.