Is it possible to quantify and stratify the kinds of pores (volume and specific surface area)? Only N2 physisorption is enough? Is there another technique to help this? Physically are there other models related to this? Thank you for your opinion and suggestions.
This is a hard task.
submicro and micropores are hard to solve by N2 adsorption, the micropore filling often superstimates the surface area calculation. If you're using BET for assessing this area, you'll have problems. Comparative plots, as t-plot and alpha-plots, often leads to mistakes as well, as some of the equations used still has microporosity, missguiding your result. There is a french author, her name is Anne Galarneau, she demonstrated in two articles how t-plot can either superestimate or overestimate micropore volume/surface area. To solve microporosity I often prefer computational methods as DFT.
Mesoporosity is fine, you can adjust BET, or even BJH (if your isotherm reaches a plateau at P/P0 >0.95), or using computational methods as well.
Macroporosity, however, you won't find answers by gas adsorption. When your material soaks, curvature upwards at the isotherm after P/P0 > 0.95, there as an alarm that your material might have pores bigger than 50 nm, however it can be only interparticle voids as well when analysing powders, so the best for this class of pores is going to mercury porosimetry or even microscopy. The microscopy won't help you on surface area, but will help you proving that your bigger pores are there. If you want to calculate the macropores volume, just subtract the total pore volume (you can use mercury picnometry for this, is quite simple, measure the geometrical volume of your sample filling a picnometer with mercury and your sample, if it's not a powder, and repeat with water, the mercury won't penetrate your piece) from the meso and micropore total volume obtained P/P0 ~0.95.
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