My textbook says that rate of chemisorption decrease with increase in pressure.
I do found a similar statement on the web but couldn't understand this.
The rate of chemisorption depends on the flux of chemical species incident on the substrate surface. High incident flux results in high chemisorption rate. As we keep on increase the pressure the incident flux gets reduced due to low diffusion length of species and hence a decrease in the rate of chemisorption. Low pressures result in larger diffusion length of chemical species towards the substrate. As a result the flux incident on substrate surface increases which eventually results in high chemisorption rate.
Any explanation for this Statement would be highly appreciated.