The adsorption of gases on solid surfaces is a critical process in various applications, such as gas separation, catalysis, and air purification. The extent of adsorption depends on several factors, including the nature of the gas, the solid surface, and the environmental conditions, such as temperature and pressure. In this response, we will discuss the effects of temperature and pressure on gas adsorption and provide examples from experimental data.1. Effect of Temperature:Temperature plays a crucial role in the adsorption process. The effect of temperature on adsorption can be understood by considering the two types of adsorption: physisorption and chemisorption.a Physisorption: In physisorption, gas molecules are adsorbed on the solid surface through weak van der Waals forces. As temperature increases, the kinetic energy of the gas molecules also increases, which weakens the attractive forces between the gas molecules and the solid surface. Consequently, physisorption decreases with increasing temperature. This behavior can be explained by the Langmuir adsorption isotherm, which predicts that the adsorption capacity decreases with increasing temperature.b Chemisorption: In chemisorption, gas molecules form chemical bonds with the solid surface. The adsorption process is accompanied by the release of energy exothermic process . According to the Le Chtelier's principle, an increase in temperature will shift the equilibrium towards the side that absorbs heat endothermic process . Therefore, chemisorption generally decreases with increasing temperature. However, at low temperatures, the activation energy required for chemisorption may not be sufficient, resulting in low adsorption. As the temperature increases, the activation energy becomes available, and chemisorption increases until it reaches a maximum value and then decreases with further increase in temperature.2. Effect of Pressure:The effect of pressure on gas adsorption can also be understood by considering physisorption and chemisorption.a Physisorption: As pressure increases, the concentration of gas molecules near the solid surface also increases, leading to an increased probability of gas molecules interacting with the solid surface. Therefore, physisorption generally increases with increasing pressure. The Langmuir and Freundlich adsorption isotherms both predict that the adsorption capacity increases with increasing pressure.b Chemisorption: The effect of pressure on chemisorption is more complex. At low pressures, chemisorption increases with increasing pressure due to the increased concentration of gas molecules near the solid surface. However, at high pressures, the adsorption sites on the solid surface may become saturated, and further increase in pressure may not significantly affect the adsorption capacity.Examples from experimental data:1. In a study by Yang et al. 2003 , the adsorption of CO2 on activated carbon was investigated. The results showed that the adsorption capacity decreased with increasing temperature, which is consistent with the physisorption process. The adsorption capacity increased with increasing pressure, reaching a maximum value at around 25 bar.2. In a study by Wu et al. 2010 , the adsorption of H2S on ZnO nanoparticles was investigated. The results showed that the adsorption capacity increased with increasing pressure and decreased with increasing temperature, indicating that the adsorption process was dominated by chemisorption.In conclusion, the adsorption of gases on solid surfaces is influenced by temperature and pressure. Physisorption generally decreases with increasing temperature and increases with increasing pressure, while chemisorption exhibits more complex behavior, with adsorption capacity typically increasing with pressure and showing a non-linear relationship with temperature. Experimental data from various studies support these trends.