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Surface Area Of Catalyst Calculator

Work out surface area of catalyst instantly with clear inputs, formula shown and shareable results.

About Surface Area Of Catalyst Calculator

BET analysis converts the gas volume needed to lay down one molecular layer into surface area. The volume at STP gives moles, moles give molecules through the Avogadro constant, and each molecule covers a known footprint - 0.162 nm2 for nitrogen at 77 K. A 2.5 cm3 monolayer on 0.2 g of catalyst works out near 54 m2/g.

Formulas

Monolayer amount

n(m) = V(m) / 22414 cm3 per mol

Specific surface area

S = n(m) x NA x sigma / sample mass

Worked example

With the default values below, Surface Area Of Catalyst Calculator returns Specific Surface Area of 54.41. Change any input above and every figure here is recalculated in your browser.

Inputs used

Monolayer gas volume adsorbed at STPminimum 0 cm3
2.5 cm3
Catalyst sample massminimum 0 g
0.2 g
Cross-sectional area of one adsorbate moleculeminimum 0 nm2
0.162 nm2

Results

Specific Surface Area
54.41 m2/g
Total Area In The Sample
10.8814 m2
Monolayer Amount Adsorbed
1.1154 × 10⁻⁴ mol
Molecules In The Monolayer
6.7169 × 10¹⁹

Step by step

  1. 1Values used
  2. 2Monolayer amount
  3. 3Specific surface area
  4. 4Specific Surface Area= 54.41 m2/g
  5. 5Total Area In The Sample= 10.8814 m2
  6. 6Monolayer Amount Adsorbed= 0.0001 mol
  7. 7Molecules In The Monolayer= 67,169,400,000,000,000,000.0000

Assumptions and limits

  • The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
  • In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
  • Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Why nitrogen at liquid nitrogen temperature?

It adsorbs weakly enough to form a well-defined monolayer, its cross-section is well established, and 77 K is easy to hold.

What surface areas are typical?

A few m2/g for dense oxides, 100-300 m2/g for alumina supports, and over 1000 m2/g for activated carbons and zeolites.

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