Comparison of Surface Areas Calculated from Nitrogen Adsorption and Mercury Porosimetry

A variety of samples with BET surface areas ranging from 1 m2/g to 760 m2/g has been examined to compare surface area calculated from nitrogen adsorption and mercury porosimetry measurements. The techniques provide comparable results with a ratio of Hg-derived surface area to N2-derived surface area, r, approximately equal to one for a specific range of BET surface areas. At BET surface areas greater than 100 m2/g or less than 10 m2/g, r frequently deviates significantly from one and factors such as particle packing and pore shape must be taken into account when comparing results from the two techniques.