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The choice of adsorbent determines the separation efficiency. Commonly used adsorbents in industry include silica gel, alumina, activated carbon, molecular sieves, and other such adsorbents； There are also special adsorption materials developed for the selective adsorption of certain components. The adsorption performance of adsorbents for various gas components is evaluated by experimentally determining the isothermal adsorption lines under static conditions and the breakthrough curves under dynamic conditions. Good adsorption performance of the adsorbent is a fundamental requirement for the adsorption separation process. In the pressure swing adsorption process, the selection of the adsorbent also requires taking into account the conflict between adsorption and desorption. On one hand, the adsorbent should have a high capacity to adsorb impurities, while at the same time the adsorbed impurities should be easy to desorb, so as to achieve adsorption-desorption equilibrium within a short period and enable the separation and purification process to continue. Another key point in selecting an adsorbent is to maximize the separation coefficient between its components. The larger the separation coefficient of the gas components, the easier the separation, and the higher the purity of the resulting product gas. At the same time, the recovery rate is also higher. During the adsorption process, as the pressure within the bed varies periodically, gas enters or exits the adsorption bed on a short time scale; as a result, the adsorbent is subject to frequent exposure to gas flow. It is therefore necessary for the adsorbent used to have sufficient strength in order to minimize fragmentation and wear. To separate gas mixtures with complex components and multiple categories, it is often necessary to use several adsorbents. These adsorbents can be packed in layers within the same adsorption bed, in order based on their adsorption separation capabilities; in some cases, they may also be placed in separate adsorption beds. It is for these reasons that the pressure swing adsorption process places special requirements on adsorbents; therefore, the adsorbents used in this process are referred to as specialized adsorbents.