Heterogeneous reaction

Gases can react on an aerosol surface. The reaction rate can be determined using the following parameterization for the reaction constant.

k=\left ( \frac{r}{D_{g}}+\frac{4}{vy} \right )^{-1}A


The reaction rate k is related to 

  • r Radius of particle
  • Dg Gas-phase diffusion coefficient
  • v Mean molecular speed
  • γ Reaction probability
  • A  Aerosol surface

Note that aerosol surface is not equivalent to effective surface (BET), due to presence of pores. 





These equations are purely deterministic and can easily be solved using a pocket calculator or spreadsheet software.

Used in 



Heterogeneous chemistry


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Read also


Consult the NanoFASE Library to see abstracts of these deliverable reports:

NanoFASE Report D6.3, Report on the laboratory tests of airborne ENM on surface transformation and atmospheric chemical reactions 

Dentener, F. J., & Crutzen, P. J. (1993), Reaction of N2O5 on tropospheric aerosols: Impact on the global distributions of NOx, O3, and OH. Journal of Geophysical Research: Atmospheres, 98(D4), 7149-7163.



  Astrid Manders

  TNO, Netherlands