The activation energies calculated for adsorbates molecules, suggested that chemisorption for BG and physisorption for MV, NOX, CPX and Cu (II) took place.
In case of pseudo-second-order kinetic model, it is possible that chemisorption is the rate-limiting step for the adsorption .
The value of activation energy, Ea, that determines the type of absorption process, whether chemisorption or physical adsorption. If the value of Ea is greater than 20 KJ/mol, is chemi-sorption where as less than 20will be physical. sbsorption
Sir I would like to ask you that if activation energy is less than 20kJ but it follows pseudo second order reaction,so process is chemisorption or physisorption
The chemisorption and physisorption prosses occur via an activation energy. The determination of the values of these energies is important to know the nature of process. I think it is the relationship between the two phenomena.
Ajaya Kumar Singh, My question is, how was the value of parameter E in the Arrhenius equation determined? Is it based on the constant k calculated from the so-called PFO or PSO?
Dear Ajaya Kumar Singh,
Regarding your question, by considering activation energy to predict any adsorption process then simply you can see If the value of Ea is lower than that of 20 KJ/mol, then the process will be physical adsorption, while in case of higher than 20 KJ/mol, the process will be considered as chemi-sorption
Ajaya Kumar Singh, The activation energy value cannot be determined based on the relationship of the lumped parameters, k1 (PFO) or k2 (PSO) on temperature. What we get with the Arrhenius equation is some number, which we can at most interpret as a measure of the sensitivity of the adsorption rate to temperature.
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