Adsorptionsenthalpie

Adsorptionsenthalpie, also known as adsorption enthalpy, is a thermodynamic quantity that describes the heat released or absorbed during the process of adsorption. Adsorption refers to the adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid to a surface, resulting in higher local concentration of the adsorbate on the surface of the adsorbent. The adsorption enthalpy quantifies the energy change associated with this surface interaction.

The value of adsorption enthalpy depends on various factors, including the nature of the adsorbate and adsorbent, the surface area available for adsorption, and the temperature at which the process occurs. Typically, physisorption (weak van der Waals forces) involves lower adsorption enthalpies, often ranging from 20 to 40 kJ/mol, while chemisorption (stronger chemical bonding) exhibits higher values, usually between 80 and 800 kJ/mol. This distinction is crucial for understanding the stability and reversibility of the adsorption process.

Experimental determination of adsorption enthalpy often relies on techniques such as calorimetry, where the heat released or absorbed during adsorption is measured directly. Alternatively, it can be inferred from adsorption isotherms or temperature-programmed desorption (TPD) studies. Adsorption enthalpy plays a key role in applications like gas storage, catalysis, and separation processes, where controlling surface interactions is essential for efficiency and selectivity.

In summary, adsorption enthalpy provides insight into the energetics of surface adsorption, influencing the design and optimization of materials for various industrial and scientific applications.