Development of highly porous activated carbons by pressurized physical activation based on the microdomain pore structure model

Abstract

The growing demand for high-performance porous carbon materials has stimulated the development of new preparation and modification techniques. Activated carbon (AC) is a representative porous carbon material and there is a need to improve its physicochemical properties, especially porosity, to upgrade and expand its areas of applications. To produce ACs, activation is a key process, because it governs the porosity. In this article, a simple method for producing ACs with a highly developed pore structure is introduced. The idea for “pressurized physical activation” came from an understanding of physical and chemical activation mechanisms based on a recognition of microdomains, which are a basic structural unit of artificial carbon materials. This new activation method produced ACs with a specific surface area larger than 2600 m²/g, which is difficult to achieve by conventional atmospheric pressure physical activation. Although chemical activation can produce ACs with a higher degree of pore development and activation yield, the new method is considered an option to provide a high degree of pore development at a relatively low-cost. Together with a high porosity, the material produced had a characteristic pore size distribution and a high bulk density. Because of these features, the superior potential of the material was demonstrated as a relatively-inexpensive and high-performance adsorbent in an adsorption heat pump system using ethanol as the refrigerant.