Role of heteroatoms (nitrogen and sulfur)-dual doped corn-starch based porous carbons for selective CO2 adsorption and separation. Issue 51 (September 2021)

• Record Type: Journal Article
• Authors: Nazir, Ghazanfar; Rehman, Adeela; Park, Soo-Jin
• Is Part Of: Journal of CO₂ utilization. Issue 51(2021)
• Publication Date: 2021-09
• Subjects: CO2 capture -- IAST CO2/N2 selectivity -- N, S co-doped -- Potassium salts -- Ultra-micropores; Carbon dioxide -- Periodicals; Carbon dioxide -- Environmental aspects -- Periodicals; Carbon dioxide mitigation -- Periodicals; Carbon dioxide; Carbon dioxide -- Environmental aspects; Carbon dioxide mitigation; Periodicals; 628.53205
• DOI: 10.1016/j.jcou.2021.101641
• Languages: English
• ISSNs: 2212-9820

Abstract

Graphical abstract: Highlights: Tuning textural and surficial characteristics by various potassium salts activation. Thiourea play an additional role in porosity generation. Samples with heteroatom (N, S)-content display excellent CO2 adsorption (269.61 mg/g). An excellent CO2 /N2 selectivity ∼ 73 was observed in K2 C2 O4 -activated sample. Abstract: Herein, we have produced two series of novel materials including heteroatoms-doped (thiourea-modified) and heteroatoms-deprived microporous carbons using three different potassium salts activators (KOH, K2 CO3, K2 C2 O4 ). The experimental results reveal that thiourea-modified KOH activated sample exhibit excellent textural features (specific surface area∼1795 m 2 /g, micropore volume∼0.82 cm 3 /g) but at the expense of a reduced heteroatom content. However, sample prepared with K2 C2 O4 exhibited a comparable specific surface area (∼1747 m 2 /g), enough population of narrow micropores (<1.0 nm), the highest micropore volume (0.93 cm 3 /g) and a high nitrogen (4.6 at. %) and sulfur content (2.3 at. %). Therefore, the optimized sample, STO, exhibits remarkable CO2 adsorption (269.61 mg/g at 0 °C and 1 bar), excellent IAST CO2 /N2 selectivity (73), high isosteric heat of adsorption (39.3 kJ/mol) and high cyclic stability, surpassing the CO2 adsorption/separation performance of most of the biomass-derived carbons. Herein, for the first time, a comprehensive study on potassium salts activation, in comparison with the conventionally practiced KOH activation, is presented. Concluding, the experimental results unveiled K2 C2 O4 as a more competitive and less corrosive potassium salt activating agent by virtue of its ability to fabricate N, S dual-doped highly porous carbons for efficient CO2 adsorption and separation.