The BET Brunauer, Emmett, and Teller theory is a widely used model to describe the multilayer adsorption of gases onto solid surfaces. According to the BET theory, the adsorption of gas molecules onto a solid surface occurs in multiple layers, with the first layer of molecules directly adsorbed onto the surface and subsequent layers forming on top of the previous ones. Temperature plays a significant role in the adsorption process, as it affects the equilibrium between adsorbed and desorbed gas molecules.As temperature increases, the kinetic energy of gas molecules also increases, which results in a higher probability of desorption from the surface. Consequently, the adsorption capacity of the solid surface decreases with increasing temperature. This is in agreement with the van't Hoff equation, which states that the adsorption equilibrium constant decreases with increasing temperature.Experimental evidence supporting the effect of temperature on multilayer adsorption can be found in various studies. For example, a study by Sing et al. 1985 investigated the adsorption of nitrogen onto activated carbon at different temperatures. The results showed that the adsorption capacity decreased with increasing temperature, which is consistent with the BET theory.Another study by Gregg and Sing 1982 examined the adsorption of argon onto silica gel at various temperatures. The results demonstrated that the adsorption capacity decreased as the temperature increased, further supporting the temperature dependence predicted by the BET theory.In summary, temperature plays a crucial role in the multilayer adsorption of gases onto solid surfaces as predicted by the BET theory. Experimental evidence from various studies supports the notion that the adsorption capacity decreases with increasing temperature, which is consistent with the theoretical predictions.