Optimal pore size design guided by GCMC molecular simulation for VOCs adsorption

Abstract

Adsorption has been proved to be an effective control method of Volatile organic compounds (VOCs). However, the design of porous carbon materials with a high VOCs adsorption performance is still a challenging topic. Herein, we proposed a novel material preparation path, namely, the synthesis of porous carbon materials guided by molecular simulation. Firstly, the optimal adsorption pore size of VOCs was calculated by grand canonical Monte Carlo (GCMC) simulation, and then cork based porous carbon with the optimal pore size controlled by urea and KOH was prepared. The sample treated at 900 °C had a specific surface area of 1940 m2/g, a total pore volume of 1.27 cm3/g, a micropore volume of 0.71 cm3/g, which showed an excellent VOCs adsorption performance at 25 °C. Specifically, the dynamic adsorption capacity of acetone and toluene were 6.1 mmol/g and 5.4 mmol/g, and the static adsorption capacity of acetone and toluene were 17.5 mmol/g (18 kPa) and 9.5 mmol/g (3 kPa), respectively. In terms of the pore size distribution, the contribution of the optimal pore sizes to the adsorption process was estimated to be about 69% for acetone and 59% for toluene. Besides, the relationship between the optimal pore size and its adsorption capacity was explored by mathematical methods, which showed a highly linear one. This study provides a novel idea for the design and optimization of excellent adsorbent materials.