Tailoring porosity in carbon spheres for fast carbon dioxide adsorption

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• 作者：Jowita Marszewska ; Mietek Jaroniec ; ^{jaroniec@kent.edu" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Carbon spheres ; Microporosity ; Mesoporosity ; Nitrogen adsorption ; CO2 adsorption
• 刊名：Journal of Colloid and Interface Science
• 出版年：2017
• 出版时间：1 February 2017
• 年：2017
• 卷：487
• 期：Complete
• 页码：162-174
• 全文大小：3541 K

文摘

Highly-porous carbon spheres were prepared by modified Stöber method combined with silica templating and CO₂ activation. Silica was delivered in the form of either colloids or tetraethyl orthosilicate and used to create porosity. Subsequently, CO₂ activation was used to develop microporosity. CO₂ activation was done either: (1) on carbon spheres, following silica etching or (2) on silica-carbon composites, before silica removal. Both methods delivered carbon materials with well-developed structures and, importantly, preserved spherical morphology. Still, activation of the silica-carbon composites with subsequent silica etching afforded carbons with better structural properties and CO₂ adsorption. Between materials prepared with silica colloids and TEOS-generated silica, the former showed more developed structures. The best material had specific surface area reaching 1500 m² g⁻¹ and total pore volume exceeding 1.2 cm³ g⁻¹ and showed CO₂ uptakes as high as 7.8 mmol g⁻¹ (0 °C, 1 bar) and 4.0 mmol g⁻¹ (23 °C, 1 bar). Mesoporosity improved mass transfer, which directly translated to faster CO₂ equilibration (30–40% on average). The proposed synthesis afforded carbons with high and fast CO₂ adsorption, which makes them good candidates for CO₂ sorption applications. Moreover, it was shown that both, microporosity and mesoporosity, are important in development of prospective CO₂ sorbents.