Micro-mesoporous activated carbon simultaneously possessing large surface area and ultra-high pore volume for efficiently adsorbing various VOCs

Abstract It is challenging to prepare biomass-based super activated carbon (SAC) simultaneously possessing a surface area larger than 2500 m2/g and a pore volume up to 2.2 cm3/g. In this research, SACs were prepared by impregnating coconut shell with H3PO4 at high impregnation ratio before suddenly heating them in CO2 flow. The SAC prepared at impregnation ratio of 3 displayed a specific surface area of 2763 m2/g, a total pore volume of 2.376 cm3/g, and a mesopore volume of 1.365 cm3/g. All these pore parameters ranked among the highest corresponding values reported for porous carbons. Because of the well-developed pore structure of this sample, its adsorption capacities for benzene, methanol, n-hexane and cyclohexane reached 1846, 1777, 1510, 1766 mg/g, respectively, all of which were high compared with the corresponding values previously reported for porous adsorbents. This sample also showed superior adsorption rate and excellent recyclability for the tested VOCs. Raising the impregnation ratio from 3 to 4 did not enhance the pore properties and VOC adsorption performance. This research provided a feasible route to manufacture biomass-based SAC which possessed simultaneously large surface area, superior pore volume, and high broad-spectrum VOC adsorption performance.