Question

Given a sample of mesoporous silica with a surface area of 500 m²/g, an amount of physisorbed nitrogen of 4.2 µmol/g, and assuming a monolayer coverage of 16.2 µmol/m², calculate the BET surface area of the silica.

Answer 1

The BET  Brunauer-Emmett-Teller  surface area is a widely used parameter to characterize the surface area of porous materials. To calculate the BET surface area, we can use the following formula:BET surface area =  Amount of physisorbed nitrogen / Monolayer coverage   Surface areaGiven the amount of physisorbed nitrogen  N  is 4.2 mol/g, the monolayer coverage  M  is 16.2 mol/m, and the surface area  S  is 500 m/g, we can plug these values into the formula:BET surface area =  4.2 mol/g  /  16.2 mol/m   500 m/gBET surface area = 0.259259259  500 m/gBET surface area  129.63 m/gTherefore, the BET surface area of the mesoporous silica is approximately 129.63 m/g.