The effect of temperature on the adsorption of gas on a solid surface can be understood through the adsorption isotherms and the thermodynamics of adsorption processes. Adsorption can be classified into two types: physisorption and chemisorption.Physisorption is a physical process where weak van der Waals forces are involved in the adsorption of gas molecules on a solid surface. In this case, the adsorption process is exothermic, meaning it releases heat. As the temperature increases, the adsorption capacity of the solid surface decreases. This is because the increased kinetic energy of the gas molecules overcomes the weak attractive forces between the gas and the solid surface. This phenomenon can be explained by the Langmuir and Freundlich isotherms, which show a decrease in adsorption capacity with increasing temperature.Chemisorption, on the other hand, involves the formation of chemical bonds between the gas molecules and the solid surface. This process is also exothermic, but the energy released is much higher than in physisorption. In chemisorption, the effect of temperature on adsorption depends on the activation energy of the reaction. At low temperatures, the adsorption capacity may be limited by the low kinetic energy of the gas molecules, which is insufficient to overcome the activation energy barrier. As the temperature increases, the adsorption capacity may increase due to the increased kinetic energy of the gas molecules, which allows them to overcome the activation energy barrier and form chemical bonds with the solid surface. However, at very high temperatures, the adsorption capacity may decrease again due to the desorption of gas molecules from the surface.Experimental data supporting these observations can be found in various studies. For example, a study by Yang et al. 2001 on the adsorption of CO2 on activated carbon showed that the adsorption capacity decreased with increasing temperature, which is consistent with the physisorption process. Another study by Ghouma et al. 2018 on the adsorption of hydrogen on metal-organic frameworks MOFs showed that the adsorption capacity increased with temperature up to a certain point, and then decreased, which is consistent with the chemisorption process.In conclusion, the effect of temperature on the adsorption of gas on a solid surface depends on the type of adsorption physisorption or chemisorption and the specific system being studied. In general, physisorption capacity decreases with increasing temperature, while chemisorption capacity may initially increase with temperature and then decrease at higher temperatures.References:1. Yang, R. T., Hernandez-Maldonado, A. J., & Yang, F. H. 2001 . Desulfurization of transportation fuels with zeolites under ambient conditions. Science, 291 5511 , 2140-2142.2. Ghouma, I., Gelin, P., & Ke, X. 2018 . Hydrogen adsorption on metal-organic frameworks: A comparison between experimental isotherms and theoretical predictions. International Journal of Hydrogen Energy, 43 37 , 17641-17654.