Combined use of gas adsorption and immersion calorimetry for the correct characterization of the narrow microporosity in carbon materials

FUEL 218

Joaquin Silvestre-Albero, joaquin.silvestre@ua.es and Francisco Rodríguez-Reinoso, reinoso@ua.es. Laboratorio de Materiales Avanzados, Departamento de Química Inorgánica, Universidad de Alicante, Ctra. San Vicente s/n, Alicante, E-03080, Spain
Textural characterization of carbon materials is commonly performed by gas adsorption (mainly N2 at 77K and CO2 at 273K). However, this approach exhibits certain limitations when dealing with samples possessing narrow microporosity, i.e. presence of diffusional restrictions and/or underestimation of the “apparent” surface area determined from N2 adsorption. Immersion calorimetry into liquids with different molecular dimensions allows the assessment of the pore size distribution of a porous solid and, it can be used to estimate the total surface area accessible to a certain liquid. Thus, the combined used of gas adsorption and immersion calorimetry is a powerful approach for the correct characterization of porous carbons where narrow microporosity is expected. In fact, immersion calorimetry overcomes important drawbacks associated with characterization using gas adsorption.