Intensity and quantity of chemisorption

From the perspective of chemisorption to catalyst research, it must first measure the intensity, adsorption capacity as well as adsorption state of chemisorption, and then understand the physical meaning of these parameters via investigation of the nature and the structure of the surface of catalysts. 

Integral adsorption heat is the average value of adsorption heat of adsorbate on the surface covered by the adsorbate in equilibrium. It reflects the average value of heat produced by adsorption process in a long period of time. 

The changes in differential adsorption heat with the surface coverage reflect the surface distribution of energy-state of adsorptive site and the intensity of adsorbate molecule bonding with the surface. The changes in adsorption heat of NH3 with the surface coverage characterize the changes of the surface acid intensity for acid catalyst. 

Finally, it should be pointed out that finding the relationship between adsorption heat and catalytic activity is difficult in the development process of catalyst due to various constraints. First, it is difficult to determine the adsorption heat, which is generally much more complex than the evaluation of catal dic activity. Second, since adsorption heat changes with the surface coverage, it is difficult to 

Langmuir monolayer adsorption model can also be used to deal with chemisorption process due to its simplicity. However, in the Langmuir adsorption model, the hypothesis of the uniformity of solid surface is different from the actual surface. So it needs necessary amendments. In the chemisorption, it often occurs with the competitive and dissociative adsorption, and their adsorption isotherm equations can be obtained by Langmuir adsorption model, respectively. 

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