Dispersion (materials science)

In materials science, dispersion is the fraction of atoms of a material exposed to the surface. In general, D = N_S/N, where D is the dispersion, N_S is the number of surface atoms and N_T is the total number of atoms of the material.^[1] It is an important concept in heterogeneous catalysis, since only atoms exposed to the surface can affect catalytic surface reactions. Dispersion increases with decreasing crystallite size and approaches unity at a crystallite diameter of about 0.1 nm.

^ Bergeret, Gérard; Gallezot, Pierre (2008), "Particle Size and Dispersion Measurements" (PDF), Handbook of Heterogeneous Catalysis, American Chemical Society, pp. 738–765, doi:10.1002/9783527610044.hetcat0038, ISBN 978-3-527-61004-4

[1] Bergeret, Gérard; Gallezot, Pierre (2008), "Particle Size and Dispersion Measurements" (PDF), Handbook of Heterogeneous Catalysis, American Chemical Society, pp. 738–765, doi:10.1002/9783527610044.hetcat0038, ISBN 978-3-527-61004-4

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