I read some publications stated that the value of enthalaply change higher than 40 kJ/mol the adsorption will be chemisorption and below this value will be physisorption he negative values of enthalpy change (ΔH) verified the exothermic nature of ... below 40 kJmol−1 are reported to depict physisorption mechanisms
Dear all, I would say there a relationship but it can not be monotonicaly generalized. Sorption involves exchange of energy (+/-), so obviously thermodynamics parameters are involved. Please take a look at the following documents. My Regards
https://www.researchgate.net/publication/328150631_Evaluation_of_thermodynamic_parameters_for_adsorption_of_heavy_metals_by_green_adsorbents#:~:text=Thermodynamic%20parameters%20%CE%94G%C2%B0%2C%20%CE%94H,(%CE%94G%C2%B0%20%3C%200).
https://doi.org/10.1155/2018/3463724
DOI: 10.5772/19514
https://www.tandfonline.com/doi/full/10.1080/23312009.2017.1351653
http://www.pjoes.com/Adsorption-Isotherm-Kinetic-r-nand-Thermodynamic-Studies-for-Methylene-Blue-r-nfrom,89392,0,2.html
There isn't any especial relation between the mechanism of adsorption and thermodynamic parameters. However, the observations have shown that for the physisorption the enthalpy is usually less than 40 kJ/mol and for the chemisorption it is higher than 80 kJ/mol.
For more information please see Atkins Physical Chemistry.
Dear all, I would say there a relationship but it can not be monotonicaly generalized. Sorption involves exchange of energy (+/-), so obviously thermodynamics parameters are involved. Please take a look at the following documents. My Regards
https://www.researchgate.net/publication/328150631_Evaluation_of_thermodynamic_parameters_for_adsorption_of_heavy_metals_by_green_adsorbents#:~:text=Thermodynamic%20parameters%20%CE%94G%C2%B0%2C%20%CE%94H,(%CE%94G%C2%B0%20%3C%200).
https://doi.org/10.1155/2018/3463724
DOI: 10.5772/19514
https://www.tandfonline.com/doi/full/10.1080/23312009.2017.1351653
http://www.pjoes.com/Adsorption-Isotherm-Kinetic-r-nand-Thermodynamic-Studies-for-Methylene-Blue-r-nfrom,89392,0,2.html
It was once agreed that if the system gives energy to the surroundings (exothermic process), it corresponds to a negative enthalpy value. If it absorbs energy, the sign is positive. Obviously, the greater the energy released to the surroundings, the greater the likelihood of chemisorption.
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