Synthesis and Characterisation of Pyridinium-Based Ionic Liquid as Activating Agent in Rubber Seed Shell Activated Carbon Production for CO2 Capture

Abstract

The use of an activating agent in chemical activation of activated carbon (AC) production is very important as it will help to open the pore structure of AC as adsorbents and could enhance its performance for adsorption capacity. In this study, a pyridinium-based ionic liquid (IL), 1-butylpyridinium bis(trifluoromethylsulfonyl) imide, [C₄Py][Tf₂N] has been synthesized by using anion exchange reaction and was characterized using few analyses such as ¹H-NMR, ¹³C-NMR and FTIR. Low-cost AC was synthesized by chemical activation process in which rubber seed shell (RSS) and ionic liquid [C₄Py][Tf₂N] were employed as the precursor and activating agent, respectively. AC has been prepared with different IL concentration (1% and 10%) at 500°C and 800°C for 2 hours. Sample AC2 shows the highest S_BET and V_T which are 392.8927 m²/g and 0.2059 cm³/g respectively. The surface morphology of synthesized AC can be clearly seen through FESEM analysis. A high concentration of IL in sample AC10 contributed to blockage of pores by the IL. On the other hand, the performance of synthesized AC for CO₂ adsorption capacity also studied by using static volumetric technique at 1 bar and 25°C. Sample AC2 contributed the highest CO₂ uptakes which is 50.783 cm³/g. This current work shows that the use of low concentration IL as an activating agent has the potential to produce porous AC, which offers low-cost, green technology as well as promising application towards CO₂ capture.