Delineating the effects of pore structure and N-doping on CO2 adsorption using coco peat derived carbon. (March 2023)

• Record Type: Journal Article
• Authors: Varghese, Soniya Mariya; Chowdhury, Additi Roy; Arnepalli, Dali Naidu; Ranga Rao, G.
• Is Part Of: Carbon trends. Number 10(2022)
• Publication Date: 2023-03
• Subjects: Coco peat -- Biomass -- CO2 adsorption -- Ultra-micropore -- Nitrogen-doped carbon; Carbon -- Periodicals; Carbon composites -- Periodicals; Carbon; Carbon composites; Periodicals; 620.193
• DOI: 10.1016/j.cartre.2023.100250
• Languages: English
• ISSNs: 2667-0569

Abstract

Highlights: Coco peat derived ultra-microporous carbon activated using melamine and KOH. Pore size distribution and nitrogen content are tuned during activation. Maximum CO2 uptake achieved is 4.8 mmol g −1 at 298 K and 1 bar. CO2 adsorption capacity is correlated with ultra-micropore volume of carbons. Nitrogen content shows no clear correlation with CO2 adsorption capacity. Abstract: The CO2 adsorption capacity of carbon materials depends on their structural properties and chemical nature of the functionalization of carbon networks. In this work, amorphous carbon materials are derived from coco peat by activation using KOH and melamine. These are studied to determine the relative influence of pore size distribution and N-doping effect on CO2 adsorption capacity at 298 K and 1 bar. Melamine is used as a pore-directing template and N-doping agent in the preparation of ultra-microporous carbons. The surface areas and ultra-micropore volumes of carbon materials are estimated by NLDFT method based on CO2 adsorption-desorption isotherms at 273 K which vary from 753 m 2 g −1 to 1702 m 2 g −1 and from 0.13 cm 3 g −1 to 0.33 cm 3 g −1, respectively. Contrary to many theoretical and experimental studies where N-doping in carbon is reported to have a positive impact on CO2 adsorption, the present study does not indicate any beneficial effect of nitrogen content in biomass-derived carbon while the pore size distribution has a profound effect on CO2 adsorption. A direct correlation has been observed between ultra-micropore (< 0.7 nm) volume and the CO2 adsorption capacity. This study demonstrates that pore size distribution can be tuned in coco peat-derived carbons to achieve maximum CO2 adsorption capacity of 4.8 mmol g −1 at 298 K and 1 bar. It is, therefore, possible to utilize biomass materials to generate carbons with suitable pore size distribution and pore volume for CO2 capture effectively at room temperature. Graphical asbtract: Image, graphical abstract