The attached result was obtained from Nitrogen adsorption at 77K of an activated carbon sample. Most of the data points lie outside the best fit curve, could it be interpreted that the sample is more or less microporous?
I will suppose you are talking about N2 adsorption at 77 K. (Not 'BET surface area analysis', to use proper nomenclature):
Your sample is highly microporous and you do not have any point at low pressure (or you didn't set your apparatus to measure low pressure, or it is not able to measure low pressure).
Micropores fill at very low pressure, then, with your experiment and this analysis you only get information from the pores larger than 3 Å (see where the t-plot starts?).
Look at the y-axis of your plot (Quantity adsorbed): you only measured data between 320 to 300 cc/g. Between 0 to 320 cc/g you don't have any information (blank area) because you don't have experimental points. Then you cannot do the proper fitting.
So yes, you can say that your (not surface) sample is microporous. This can also be check by inspection of your isotherm: probably type-I.
Thanks Fernando Vallejos-Burgos. I have made the suggested changes to my question.
This analysis was not performed by me. I am just trying to understand this data because I have to perform a similar analysis. Since the instrument I have can't be used for analysis at low pressure, I am hoping to get a better idea about the sample by determination of iodine number.
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