Development of Porous Template Carbons from Montmorillonite Clays and Evaluation of Their Toluene Adsorption Behaviors

• Published in: Aerosol and Air Quality Research 2013-12, Vol.13 (6), p.1779-1789
• Main Authors: Hseu, Zeng-Yei, Hsi, Hsing-Cheng, Syu, Jhih-Siang, Wang, Li-Chun
• Format: Article
• Language: English
• ISSN: 1680-8584; 2071-1409
• DOI: 10.4209/aaqr.2012.11.0301

Carbon replicas were developed with two montmorillonites as the template and sucrose as the carbon source. The fabrication procedures included sucrose doping, polymerization with H 2 SO 4 , carbonization at 500–900°C, and liberation of carbon replicas from the template skeleton. N 2 adsorption isotherms indicated the all of the resulting carbon replicas contained both micropores and mesopores. A higher carbonization temperature typically led to greater initial N 2 adsorption, suggesting the presence of a greater number of micropores. Since no measurable micropores were found in the parent montmorillonites, those observed in the carbon replicas may have developed via activation of inherent water due to dehydration of montmorillonite clay or sucrose during the high temperature carbonization. XRD examination confirmed the formation of both graphite-like structure and amorphous carbon. The C content, C/H molar ratio, and the extent of π-electron resonance of the carbon replicas increased as the carbonization temperature rose, indicating that a higher temperature caused more thorough carbonization in the montmorillonite templates. Toluene adsorption experiments at 1000–8000 ppm v and 30–90°C demonstrated the effectiveness of carbon replicas with regard to capturing toluene. Model simulations further suggest that pore filling of toluene inside the mesopores of template carbon may occur, because the adsorption data showed better agreement with the DR model.