Porous structure analysis of coconut shell–derived activated carbons prepared under different conditions

TL;DR

This paper studies how different preparation conditions affect the porous structure of activated carbons made from coconut shells.

Contribution

The study reveals the impact of activation temperature and precursor-to-activator mass ratio on the porous structure of nitrogen-doped activated carbons.

Findings

Activation at 700°C with a 3 or 4 mass ratio yields activated carbons with the highest microporous structure.

These materials also exhibit the lowest surface heterogeneity.

The study used advanced methods like quenched solid density functional theory for analysis.

Abstract

This paper presents original results of the analysis of the influence of preparation conditions on the formation of the porous structure of activated carbons derived from coconut shells and doped with nitrogen by combining ammoxidation with potassium hydroxide chemical activation. The clustering-based adsorption analysis process, the quenched solid density functional theory, and the non-local density functional theory methods were used in the analyses. Based on the obtained results, a significant effect of both the activation temperature and the mass ratio of precursor to chemical activator on the formation of the porous structure of the prepared activated carbons was observed. The materials with the best adsorption properties were the activated carbons prepared at 700 °C with mass ratios of raw material to chemical activator of 3 and 4. These materials were characterised not only by the highest development of the microporous structure, as indicated by the VhA values i.e.: 1.563 cm³/g and 1.542 cm³/g, respectively, but also by the lowest degree of surface heterogeneity, as suggested by the surface heterogeneity parameter h = 1.

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