# 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.

## Execution

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

## Used in

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

## Contact

Astrid Manders

TNO, Netherlands